Greentree Elementary: math

The shaded band is this school's normal range. If nothing about how it works changes, nearly every future year should land inside it. Zero means the typical student just meets the state standard. The small numbers under the years are how many students were tested.

Step 1 · Each year's result

For each grade tested, take the average (mean) scale score from the California Department of Education's results file, and subtract the lowest score that counts as "Standard Met" for that grade. That is the grade's distance from standard. Weight each grade by its share of the students tested, then add the grades up. Grades where the state hides the average because ten or fewer students tested are left out entirely.

2015 from sb_ca2015_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	53,127	2462.1	− 2436	26.1	× 77 / 307	6.5
4	53,130	2488.2	− 2485	3.2	× 59 / 307	0.6
5	53,131	2510.7	− 2528	−17.3	× 84 / 307	−4.7
6	53,134	2565.2	− 2552	13.2	× 87 / 307	3.7
Sum, rounded to a whole point						6

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,368	2465.3	− 2436	29.3	× 84 / 312	7.9
4	49,369	2509.5	− 2485	24.5	× 77 / 312	6
5	49,371	2516.6	− 2528	−11.4	× 62 / 312	−2.3
6	49,374	2564.6	− 2552	12.6	× 89 / 312	3.6
Sum, rounded to a whole point						15

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	50,732	2461.6	− 2436	25.6	× 63 / 276	5.8
4	50,734	2514.2	− 2485	29.2	× 75 / 276	7.9
5	50,736	2523.6	− 2528	−4.4	× 73 / 276	−1.2
6	50,738	2573.5	− 2552	21.5	× 65 / 276	5.1
Sum, rounded to a whole point						18

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	50,768	2462.4	− 2436	26.4	× 62 / 273	6
4	50,770	2498.7	− 2485	13.7	× 63 / 273	3.2
5	50,772	2528.0	− 2528	0	× 81 / 273	0
6	50,774	2581.7	− 2552	29.7	× 67 / 273	7.3
Sum, rounded to a whole point						16

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	50,975	2463.7	− 2436	27.7	× 73 / 282	7.2
4	50,976	2490.3	− 2485	5.3	× 64 / 282	1.2
5	50,977	2515.2	− 2528	−12.8	× 63 / 282	−2.9
6	50,978	2570.6	− 2552	18.6	× 82 / 282	5.4
Sum, rounded to a whole point						11

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	50,901	2449.7	− 2436	13.7	× 62 / 257	3.3
4	50,902	2482.6	− 2485	−2.4	× 56 / 257	−0.5
5	50,903	2531.2	− 2528	3.2	× 65 / 257	0.8
6	50,904	2561.8	− 2552	9.8	× 74 / 257	2.8
Sum, rounded to a whole point						6

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	50,867	2440.2	− 2436	4.2	× 68 / 256	1.1
4	50,868	2475.9	− 2485	−9.1	× 66 / 256	−2.3
5	50,869	2509.2	− 2528	−18.8	× 56 / 256	−4.1
6	50,870	2575.6	− 2552	23.6	× 66 / 256	6.1
Sum, rounded to a whole point						1

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	50,728	2457.0	− 2436	21	× 70 / 265	5.5
4	50,729	2467.7	− 2485	−17.3	× 69 / 265	−4.5
5	50,730	2506.2	− 2528	−21.8	× 66 / 265	−5.4
6	50,731	2541.8	− 2552	−10.2	× 60 / 265	−2.3
Sum, rounded to a whole point						−7

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	50,490	2443.2	− 2436	7.2	× 58 / 259	1.6
4	50,491	2515.5	− 2485	30.5	× 65 / 259	7.7
5	50,492	2487.3	− 2528	−40.7	× 67 / 259	−10.5
6	50,493	2555.0	− 2552	3	× 69 / 259	0.8
Sum, rounded to a whole point						0

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. 6, 15, 18, 16, 11, 6, 1, −7, 0 → 7.3
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 9 · 2016→2017: 3 · 2017→2018: 2 · 2018→2019: 5 · 2019→2022: 5 · 2022→2023: 5 · 2023→2024: 8 · 2024→2025: 7 → average 5.5
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 5.5 × 2.66 = 14.6. Upper limit 21.9, lower limit −7.3.

Why 2.66? It is the standard factor from quality control, the work of Walter Shewhart and W. Edwards Deming. It turns "how much the result typically changes in a year" into "how far it can wander by chance alone".

Years with no result (no state tests were given in spring 2020) are skipped: the year-to-year change runs from the last year with a result to the next one.

Step 3 · Free or reduced-price meals

The share of enrolled students eligible for free or reduced-price meals. From 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.