Is Flagstone Elementary School a good school?

Flagstone Elementary School ranks 186 th of 943 Colorado elementary schools. SchoolDigger rates this school 4 stars out of 5.

How many students attend Flagstone Elementary School?

In the 2022-23 school year, 470 students attended Flagstone Elementary School.

What is the racial makeup of Flagstone Elementary School?

Students at Flagstone Elementary School are 77% White, 16% Hispanic, 6% Two or more races.

What schools do graduates of Flagstone Elementary School attend?

Students who attend Flagstone Elementary School usually go on to attend: Middle : Mesa Middle School High : Douglas County High School

Flagstone Elementary School

Summary:

Flagstone Elementary School is a public elementary school in Castle Rock, Colorado, serving 470 students in grades PK-6 as part of the highly-ranked Douglas County School District No. Re 1. The school consistently performs above state and district averages in academic assessments, with 64.8% of students proficient or better in English Language Arts and 49.8% in Math, compared to 62.3% and 52.3% for the district, respectively.

Flagstone Elementary's strong academic performance is further highlighted by its ranking, moving from 453rd out of 929 Colorado elementary schools in 2016-2017 to 186th out of 943 in 2023-2024. However, the school's performance for certain student subgroups, such as male students and white students, is more average compared to female students. Additionally, Flagstone has a higher chronic absenteeism rate of 19.0% compared to the district average of 13.7%.

While Flagstone Elementary outperforms many nearby public schools, it lags behind some high-performing charter schools in the area, such as Aspen View Academy and Academy Charter School. The school's relatively low percentage of free/reduced lunch recipients, at 11.49%, suggests it may serve a more affluent student population, which could contribute to its stronger academic performance.

Detail:

Public PK, KG-6

104 Lovington Street
Castle Rock, CO 80104-8707

(303) 387-5225

District: Douglas County School District No. Re 1

SchoolDigger Rank:
186^th of 943 Colorado Elementary Schools

Per Pupil Expenditures: $13,758

Students who attend Flagstone Elementary School usually attend:

Middle:	Mesa Middle School
High:	Douglas County High School

Student/teacher ratio: 17.7

Number of students: 470

Racial breakdown:

White:

76.6%

Hispanic:

15.7%

Two or more races:

5.5%

Free/discounted lunch recipients: 11.5%

See top rated Colorado elementary schools

Compare Flagstone Elementary School to nearby elementary schools!

Performance Trends

Compare Details Flagstone Elementary School ranks better than 80.3% of elementary schools in Colorado. It also ranks 30^th among 58 ranked elementary schools in the Douglas County School District No. Re 1. (See more...)

Compare Details In 2024 the calculated Average Standard Score was 78.13. (See more...)

Chronic absenteeism in a school refers to a situation where students repeatedly miss school, with the threshold often defined as missing 10% or more of school days for any reason, excused or unexcused.

Student Body

Compare Details Flagstone Elementary School has the largest elementary school student body size in the Douglas County School District No. Re 1. (See more...)

Compare Details

Teachers

Compare Details

Compare

Finance

Compare Details The average total spent per student at Flagstone Elementary School is $13,758. 46 elementary schools in the Douglas County School District No. Re 1 spend more per student.

Schooldigger 2024 Rankings:

Flagstone Elementary School:

SchoolDigger ranks Flagstone Elementary School 186^th of 943 Colorado public elementary schools. (See Flagstone Elementary School in the ranking list.)

Elementary School Test Score Ratings by Student Subgroup:

Female students:

Male students:

White students:

Douglas County School District No. Re 1:

SchoolDigger ranks Douglas County School District No. Re 1 5^th of 116 Colorado school districts. (See district ranking list.)

Average Parent Rating:

Read all reviews and ratings detail for Flagstone Elementary School.

What do you think?

Your rating for Flagstone Elementary School?

(Ranking FAQ)

Rank History for Flagstone Elementary School

Compare

Rank History for all students at Flagstone Elementary School

Year	Avg Standard Score	Statewide Rank	Total # Ranked Elementary Schools	CO State Percentile
2004	77.32	175^th	808	78.3%
2005	83.96	90^th	823	89.1%
2006	78.73	145^th	829	82.5%
2007	63.05	339^th	852	60.2%
2008	71.16	242^nd	849	71.5%
2009	78.17	174^th	872	80.0%
2010	74.32	220^th	925	76.2%
2011	76.49	205^th	935	78.1%
2012	75.25	218^th	935	76.7%
2013	73.23	244^th	954	74.4%
2014	67.62	298^th	962	69.0%
2015	61.43	316^th	938	66.3%
2016	53.92	380^th	914	58.4%
2017	45.26	453^rd	929	51.2%
2018	62.42	308^th	917	66.4%
2019	60.34	363^rd	965	62.4%
2021	64.29	270^th	710	62.0%
2022	83.68	122^nd	921	86.8%
2023	83.79	131^st	933	86.0%
2024	78.13	186^th	943	80.3%

See the entire list of Colorado Elementary School Rankings!

Rank History for Female students at Flagstone Elementary School

Year	Avg Standard Score	Statewide Rank	Total # Ranked Elementary Schools	CO State Percentile
2018	57.83	257^th	690	62.8%
2019	52.72	325^th	758	57.1%
2021	55.77	189^th	351	46.2%
2022	86.25	58^th	595	90.3%
2023	81.44	93^rd	642	85.5%
2024	70.59	186^th	684	72.8%

See the entire list of Best Colorado Elementary Schools for Female Students!

Rank History for Male students at Flagstone Elementary School

Year	Avg Standard Score	Statewide Rank	Total # Ranked Elementary Schools	CO State Percentile
2018	52.00	289^th	693	58.3%
2019	55.53	304^th	764	60.2%
2021	54.38	190^th	352	46.0%
2022	66.40	186^th	594	68.7%
2023	72.87	158^th	649	75.7%
2024	70.10	183^rd	683	73.2%

See the entire list of Best Colorado Elementary Schools for Male Students!

Rank History for White students at Flagstone Elementary School

Year	Avg Standard Score	Statewide Rank	Total # Ranked Elementary Schools	CO State Percentile
2018	48.90	166^th	337	50.7%
2019	38.09	372^nd	596	37.6%
2022	58.22	192^nd	454	57.7%
2023	64.61	177^th	525	66.3%
2024	59.46	219^th	539	59.4%

See the entire list of Best Colorado Elementary Schools for White Students!

Data source: test scores: Colorado Department of Education, rankings: SchoolDigger.com

As you review the school rankings data, please be aware that some of the information from certain demographics is missing. The reason for this omission is that the data has been redacted from the source data itself due to low population samples in these specific demographic groups.

Redacting data from low population samples is a necessary step to ensure the reliability and accuracy of the results, as small sample sizes may not be representative of the broader population. Additionally, this measure helps protect the privacy of individuals belonging to these demographic groups.

Data source: Colorado Department of Education

Review counts

All ratings (Avg rating: 2.3)

33%

67%

Reviews:

by a parent
Friday, April 12, 2013

Unlike the earlier comments I found the interim principle Nancy Wortmann to be competent, professional and well liked by the students and faculty. The one year wonder prior did a lot of harm and Nancy brought stability.

The current VP Kelli Smith was just named to the post and I hope she continues to make the practical decisions and provide the same leadership.

Yes there are occasions where small children "collect" things like items they find in lost and found and we diligently ensured our daughter learned the difference and alerted her 1st grade teacher, no more issues and those few in the class that seemed prone to collect things have been counseled and it stopped.

My daughter is the youngest in her class and that has a major impact on performance. The school assembed a team that has planned, invested and executed in an individualized program that has paid off big time. She loves school now, especially reading and her grades and performance is now on par with the best older students in the class.

Yes I wish the teacher to student ratio was better, but this school delivers and has a lot of reason for parents and studnts to show their Mustang pride. Close Quote

by a parent
Thursday, January 17, 2013

Too many kids in classrooms, no teacher aids or assistants, theft a big problem, terrible principle. Close Quote

Enrollment information for Flagstone Elementary School

Compare

Year	White	African American	Asian	Hispanic	American Indian	Pacific Islander	Two or More Races	Total
2004	352	13	6	26	8	n/a	n/a	405
2005	447	7	14	30	7	n/a	n/a	505
2006	568	12	12	47	10	n/a	n/a	649
2007	537	10	6	40	9	n/a	n/a	602
2008	610	7	8	62	10	n/a	n/a	697
2009	643	10	8	70	11	n/a	n/a	742
2010	664	10	11	73	7	n/a	n/a	765
2011	569	7	5	77	4	2	28	692
2012	556	8	5	69	1	3	31	673
2013	538	13	6	68	0	3	34	662
2014	479	8	5	58	3	2	32	587
2015	494	4	11	76	4	2	44	635
2016	459	3	7	63	1	5	33	571
2017	417	1	8	64	0	5	39	534
2018	397	4	8	65	1	4	29	508
2019	390	4	6	74	0	2	21	497
2020	394	2	5	62	2	2	22	489
2021	335	3	3	71	7	1	18	438
2022	331	3	3	66	7	0	22	432
2023	360	3	4	74	3	0	26	470

Data source: National Center for Education Statistics, U.S. Dept of Education.

About Enrollment/Ethnicity

For more information about how the Department of Education defines ethnicity, see Defining Race and Ethnicity Data, National Center for Education Statistics

Students eligible for free or discounted lunch at Flagstone Elementary School

Compare

Year	# Students	Full-time Teachers	Student/Teacher ratio	% Free/Discounted Lunch
2004	405	21.1	19.2	8.1
2005	505	26.7	18.9	5.5
2006	649	33.4	19.4	6.2
2007	602	35.5	17.0	8.3
2008	697	35.5	19.6	7
2009	742	40.5	18.3	7.3
2010	765	41.6	18.3	10.1
2011	692	33.5	20.6	10.8
2012	673	32.0	21.0	11.4
2013	662	32.5	20.3	13.1
2014	587	34.6	16.9	16.2
2015	635	33.0	19.2	14.3
2016	571	30.0	19.0	12.8
2017	534	26.8	19.9	12.7
2018	508	27.0	18.8	12.6
2019	497	26.0	19.1	10.3
2020	489	26.0	18.8	10.6
2021	438	26.0	16.8	11.6
2022	432	27.5	15.7	12.7
2023	470	26.5	17.7	11.5

Data source: National Center for Education Statistics, U.S. Dept of Education.

About Students eligible for discounted/free lunch:

The National School Lunch Program (NSLP) provides low-cost or free meals to students in U.S. public and nonprofit private schools based on household income. Those with incomes below 130% of the poverty line receive free lunch, while those between 130% and 185% qualify for reduced-price lunch. The percentage of students receiving free or reduced-price lunch serves as a marker for poverty, as it reflects the socioeconomic status of families in a given school or district. A higher FRPL rate typically indicates a higher concentration of low-income families, suggesting that the school or district may face additional challenges in providing adequate resources and support for student success.

Student/Teacher Ratio Flagstone Elementary School

Compare

Year	# Students	Full-time Teachers	Student/Teacher ratio	% Free/Discounted Lunch
2004	405	21.1	19.2	8.1
2005	505	26.7	18.9	5.5
2006	649	33.4	19.4	6.2
2007	602	35.5	17.0	8.3
2008	697	35.5	19.6	7
2009	742	40.5	18.3	7.3
2010	765	41.6	18.3	10.1
2011	692	33.5	20.6	10.8
2012	673	32.0	21.0	11.4
2013	662	32.5	20.3	13.1
2014	587	34.6	16.9	16.2
2015	635	33.0	19.2	14.3
2016	571	30.0	19.0	12.8
2017	534	26.8	19.9	12.7
2018	508	27.0	18.8	12.6
2019	497	26.0	19.1	10.3
2020	489	26.0	18.8	10.6
2021	438	26.0	16.8	11.6
2022	432	27.5	15.7	12.7
2023	470	26.5	17.7	11.5

Data source: National Center for Education Statistics, U.S. Dept of Education.

About Student-Teacher Ratio

Student/teacher ratio is calculated by dividing the total number of students by the total number of full-time equivalent teachers. Please note that a smaller student/teacher ratio does not necessarily translate to smaller class size. In some instances, schools hire teachers part time, and some teachers are hired for specialized instruction with very small class sizes. These and other factors contribute to the student/teacher ratio. Note: For private schools, Student/teacher ratio may not include Pre-Kindergarten.

Finances

Per Pupil Expenditures for Flagstone Elementary School

Year	Total Expenditures Per Pupil
2019	$10,800
2020	$11,184
2021	$11,993
2022	$13,160
2023	$13,758

Data source: Colorado Department of Education

Pre and Post Pandemic Data

Impact of COVID-19 on Flagstone Elementary School

The coronavirus has had a profound impact on education in America. Learning shifted online overnight, attendance numbers dwindled, and enrollment decreased. SchoolDigger.com is making it easier for you to better assess how COVID-19 has impacted your school. Through the collection of pre-pandemic (2019) and current data, SchoolDigger.com is sharing test scores, enrollment numbers and school demographics from schools across the country – and we make it easy to see how impacted schools compare locally and statewide.

Rankings

Rank Pre-pandemic (2018-2019)	Rank Post pandemic (2022-2023)	Change (%)
Ranks 363^rd of 965 Elementary schools	Ranks 131^st of 933 Elementary schools	23.6%

Test Scores

	% proficient Pre-pandemic (2018-2019)	% proficient Post pandemic (2022-2023)	Change (%)
3rd Grade English Language Arts (Flagstone Elementary School)	44.8	52.9	8.1%
3rd Grade English Language Arts (Douglas County School District No. Re 1)	52	58	6%
3rd Grade English Language Arts (Colorado)	41.3	39.9	1.4%
3rd Grade Math (Flagstone Elementary School)	51.7	50.7	1%
3rd Grade Math (Douglas County School District No. Re 1)	52.6	59.4	6.8%
3rd Grade Math (Colorado)	41	40.4	0.6%
4th Grade English Language Arts (Flagstone Elementary School)	43.5	66.2	22.7%
4th Grade English Language Arts (Douglas County School District No. Re 1)	59	59.2	0.2%
4th Grade English Language Arts (Colorado)	48	43.8	4.2%
4th Grade Math (Flagstone Elementary School)	29	55.9	26.9%
4th Grade Math (Douglas County School District No. Re 1)	44.7	48.8	4.1%
4th Grade Math (Colorado)	33.6	32.7	0.9%
5th Grade Science (Flagstone Elementary School)	48.4	51.9	3.5%
5th Grade Science (Douglas County School District No. Re 1)	47.7	50.7	3%
5th Grade Science (Colorado)	35.9	33.9	2%
5th Grade English Language Arts (Flagstone Elementary School)	54	70.6	16.6%
5th Grade English Language Arts (Douglas County School District No. Re 1)	59.1	64.5	5.4%
5th Grade English Language Arts (Colorado)	48.4	47.8	0.6%
5th Grade Math (Flagstone Elementary School)	48.4	53.8	5.4%
5th Grade Math (Douglas County School District No. Re 1)	44.8	52.4	7.6%
5th Grade Math (Colorado)	35.7	36.5	0.8%
6th Grade English Language Arts (Flagstone Elementary School)	50.7	73.7	23%
6th Grade English Language Arts (Douglas County School District No. Re 1)	60.3	65.1	4.8%
6th Grade English Language Arts (Colorado)	43.6	43.4	0.2%
6th Grade Math (Flagstone Elementary School)	38.8	68.4	29.6%
6th Grade Math (Douglas County School District No. Re 1)	45.1	47.7	2.6%
6th Grade Math (Colorado)	29.5	28.2	1.3%
All Grades English Language Arts (Flagstone Elementary School)	48.2	65.2	17%
All Grades English Language Arts (Douglas County School District No. Re 1)	56.7	61.6	4.9%
All Grades English Language Arts (Colorado)	45.8	43.7	2.1%
All Grades Math (Flagstone Elementary School)	41.5	57	15.5%
All Grades Math (Douglas County School District No. Re 1)	46.5	50.7	4.2%
All Grades Math (Colorado)	34.7	32.9	1.8%

Student Body

	Number of students Pre-pandemic (2018-2019)	Number of students Post pandemic (2022-2023)	Change (%)
Total Students	497	470	5.4%
African American	4	3	25%
American Indian	0	3
Asian	6	4	33.3%
Hispanic	74	74
Pacific Islander	2	0	100%
White	390	360	7.7%
Two or More Races	21	26	23.8%
% Free/Discounted Lunch Recipients	10.3%	11.5%	1.2%

Schools Near Flagstone Elementary School

Choose columns to see: Summary School Students/Teachers Ranking Test Scores Finance All

School													Students/Teachers											Ranking (2024)				Ranking (2023)				CMAS English Language Arts (2024)							CMAS Math (2024)							CMAS Science (2024)		Per Pupil Expenditures (2023)
Name	Type	Grades	Address	City	Zip	County	District	Is Charter	Is Magnet	Is Virtual	Is Title I	Phone	Enrollment	Full-time Teachers	Student/ Teacher Ratio	Free/Discounted Lunch Recipients	White	Black	Hispanic	Asian	American Indian	Pacific Islander	Two or More Races	Average Standard Score (2024)	Statewide Rank (2024)	State Percentile (2024)	SchoolDigger Rating (2024)	Average Standard Score (2023)	Statewide Rank (2023)	State Percentile (2023)	Rank Change from Previous Year	CMAS English Language Arts 3rd Grade	CMAS English Language Arts 4th Grade	CMAS English Language Arts 5th Grade	CMAS English Language Arts 6th Grade	CMAS English Language Arts 7th Grade	CMAS English Language Arts 8th Grade	CMAS English Language Arts All Grades	CMAS Math 3rd Grade	CMAS Math 4th Grade	CMAS Math 5th Grade	CMAS Math 6th Grade	CMAS Math 7th Grade	CMAS Math 8th Grade	CMAS Math All Grades	CMAS Science 5th Grade	CMAS Science 8th Grade	Total
Flagstone Elementary School	Public	PK, KG-6	104 Lovington Street	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	No	No	No	No	(303) 387-5225	470	27	17.7	11.5%	360 (76.6%)	3 (0.6%)	74 (15.7%)	4 (0.9%)	3 (0.6%)	0 (0.0%)	26 (5.5%)	78.1	186^th of 943 public elementary schools	80.3%		83.8	131^st of 933 public elementary schools	86.0%	55	50.0	68.6	69.7	71.4			64.8	47.6	49.3	48.5	55.1			49.8	54.5		$13,758
Rock Ridge Elementary School	Public	PK, KG-6	400 North Heritage Road	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	No	No	No	No	(303) 387-5150	475	30	15.8	14.1%	333 (70.1%)	3 (0.6%)	98 (20.6%)	8 (1.7%)	3 (0.6%)	1 (0.2%)	29 (6.1%)	44.2	488^th of 943 public elementary schools	48.3%		36.9	543^rd of 933 public elementary schools	41.8%	55	50.0	32.8	44.1	50.9			44.0	47.8	28.1	18.6	36.4			31.8	28.8		$15,802
Sage Canyon Elementary	Public	PK, KG-6	2420 Autumn Sage Street	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	No	No	No	No	(720) 433-0110	570	33	17.5	8.1%	440 (77.2%)	9 (1.6%)	71 (12.5%)	8 (1.4%)	1 (0.2%)	1 (0.2%)	40 (7.0%)	77.1	195^th of 943 public elementary schools	79.3%		70.2	249^th of 933 public elementary schools	73.3%	54	64.0	50.7	57.5				57.5	71.1	34.7	64.0				57.4	55.6		$14,267
Franktown Elementary School	Public	PK, KG-5	1384 North State Highway 83	Franktown	80116	Douglas County	Douglas County School District No. Re 1	No	No	No	No	(303) 387-5300	365	22	16.4	6.3%	308 (84.4%)	3 (0.8%)	28 (7.7%)	5 (1.4%)	4 (1.1%)	0 (0.0%)	17 (4.7%)	83.3	136^th of 943 public elementary schools	85.6%		75.4	205^th of 933 public elementary schools	78.0%	69	59.3	68.0	68.5				65.0	69.5	62.0	47.2				59.9	52.8		$15,044
South Ridge Elementary An IB World School	Public	K-5	1100 South Street	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	No	No	No	Yes	(303) 387-5075	411	28	14.7	34.3%	244 (59.4%)	12 (2.9%)	130 (31.6%)	6 (1.5%)	2 (0.5%)	1 (0.2%)	16 (3.9%)	40.7	519^th of 943 public elementary schools	45.0%		33.9	571^st of 933 public elementary schools	38.8%	52	40.5	38.0	47.2				42.1	38.6	15.4	34.5				29.1	36.4		$16,288
Castle Rock Elementary School	Public	PK, KG-6	1103 Canyon Drive	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	No	No	No	No	(303) 387-5000	449	28	16.0	27.6%	275 (61.2%)	5 (1.1%)	126 (28.1%)	11 (2.4%)	1 (0.2%)	0 (0.0%)	31 (6.9%)	69.8	265^th of 943 public elementary schools	71.9%		58.4	357^th of 933 public elementary schools	61.7%	92	66.7	46.9	48.1	58.3			55.0	62.7	37.3	50.0	40.8			47.8	51.0		$15,334
Renaissance Expedition Learn Outward Bound School	Public, Magnet	K-6	3960 Trailboss Lane	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	No	Yes	No	No	(303) 387-8000	381	21	17.9	3.4%	320 (84.0%)	5 (1.3%)	30 (7.9%)	5 (1.3%)	0 (0.0%)	0 (0.0%)	21 (5.5%)	68.5	282^nd of 943 public elementary schools	70.1%		71.3	237^th of 933 public elementary schools	74.6%	45	43.4	48.0	71.4	70.6			57.5	43.4	33.3	44.6	51.4			42.7	62.5		$14,174
World Compass Academy	Public, Charter	PK, KG-8	2490 South Perry Street	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	Yes	No	No	No	(303) 814-5200	711	46	15.5	9.6%	472 (66.4%)	12 (1.7%)	133 (18.7%)	20 (2.8%)	0 (0.0%)	0 (0.0%)	74 (10.4%)	69.4	271^st of 943 public elementary schools	71.3%		60.9	336^th of 933 public elementary schools	64.0%	65	53.2	49.3	55.7	64.7	70.5	66.7	58.5	60.8	40.6	54.1	23.5	52.3	58.3	47.3	59.0	61.1	$11,872
Academy Charter School	Public, Charter	PK, KG-8	1551 Prairie Hawk Drive	Castle Rock	80104	Douglas County	Douglas County School District No. Re 1	Yes	No	No	No	(303) 660-4881	582	38	15.5	4.6%	459 (78.9%)	5 (0.9%)	63 (10.8%)	20 (3.4%)	2 (0.3%)	1 (0.2%)	32 (5.5%)	83.8	132^nd of 943 public elementary schools	86.0%		76.1	194^th of 933 public elementary schools	79.2%	62	62.5	57.8	60.3	83.6	82.0	88.9	71.7	62.5	50.0	55.6	61.2	60.3	75.6	60.1	56.5	88.9	$8,694
Aspen View Academy	Public, Charter	PK, KG-8	2131 Low Meadow Blvd	Castle Rock	80109	Douglas County	Douglas County School District No. Re 1	Yes	No	No	No	(720) 733-3436	961	54	17.8	3.9%	783 (81.5%)	6 (0.6%)	109 (11.3%)	15 (1.6%)	6 (0.6%)	0 (0.0%)	42 (4.4%)	72.9	233^rd of 943 public elementary schools	75.3%		66.2	283^rd of 933 public elementary schools	69.7%	50	65.4	58.4	64.7	62.4	60.0	53.7	61.0	55.8	35.6	48.0	39.8	42.9	30.5	42.6	47.5	30.5	$9,663

Flagstone Elementary School

Flagstone Elementary School:

Elementary School Test Score Ratings by Student Subgroup:

Douglas County School District No. Re 1:

Average Parent Rating:

What do you think?

Rank History for Flagstone Elementary School

Rank History for all students at Flagstone Elementary School

Rank History for Female students at Flagstone Elementary School

Rank History for Male students at Flagstone Elementary School

Rank History for White students at Flagstone Elementary School

Review counts

Enrollment information for Flagstone Elementary School

Students eligible for free or discounted lunch at Flagstone Elementary School

Student/Teacher Ratio Flagstone Elementary School

Per Pupil Expenditures for Flagstone Elementary School

Impact of COVID-19 on Flagstone Elementary School

Rankings

Test Scores

Student Body

Schools Near Flagstone Elementary School