Chatom Union: math

The shaded band is this district'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	96,533	2417.5	− 2436	−18.5	× 54 / 387	−2.6
4	96,534	2443.9	− 2485	−41.1	× 75 / 387	−8
5	96,537	2454.8	− 2528	−73.2	× 64 / 387	−12.1
6	96,538	2483.0	− 2552	−69	× 73 / 387	−13
7	96,541	2515.3	− 2567	−51.7	× 61 / 387	−8.1
8	96,542	2568.2	− 2586	−17.8	× 60 / 387	−2.8
Sum, rounded to a whole point						−47

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	89,535	2413.5	− 2436	−22.5	× 62 / 393	−3.5
4	89,537	2444.0	− 2485	−41	× 57 / 393	−5.9
5	89,538	2453.0	− 2528	−75	× 73 / 393	−13.9
6	89,541	2471.3	− 2552	−80.7	× 64 / 393	−13.1
7	89,543	2494.5	− 2567	−72.5	× 75 / 393	−13.8
8	89,544	2551.7	− 2586	−34.3	× 62 / 393	−5.4
Sum, rounded to a whole point						−56

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,142	2415.2	− 2436	−20.8	× 63 / 385	−3.4
4	92,144	2437.5	− 2485	−47.5	× 63 / 385	−7.8
5	92,147	2464.9	− 2528	−63.1	× 53 / 385	−8.7
6	92,149	2469.3	− 2552	−82.7	× 69 / 385	−14.8
7	92,151	2477.3	− 2567	−89.7	× 62 / 385	−14.4
8	92,152	2538.3	− 2586	−47.7	× 75 / 385	−9.3
Sum, rounded to a whole point						−58

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,342	2434.6	− 2436	−1.4	× 65 / 365	−0.2
4	92,343	2453.4	− 2485	−31.6	× 65 / 365	−5.6
5	92,346	2469.3	− 2528	−58.7	× 59 / 365	−9.5
6	92,347	2502.3	− 2552	−49.7	× 52 / 365	−7.1
7	92,350	2490.0	− 2567	−77	× 67 / 365	−14.1
8	92,351	2561.7	− 2586	−24.3	× 57 / 365	−3.8
Sum, rounded to a whole point						−40

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,977	2419.5	− 2436	−16.5	× 57 / 385	−2.4
4	92,978	2460.5	− 2485	−24.5	× 69 / 385	−4.4
5	92,979	2467.6	− 2528	−60.4	× 66 / 385	−10.4
6	92,980	2494.2	− 2552	−57.8	× 65 / 385	−9.8
7	92,981	2515.5	− 2567	−51.5	× 55 / 385	−7.4
8	92,982	2539.4	− 2586	−46.6	× 73 / 385	−8.8
Sum, rounded to a whole point						−43

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	91,004	2388.7	− 2436	−47.3	× 61 / 377	−7.7
4	91,005	2445.5	− 2485	−39.5	× 63 / 377	−6.6
5	91,006	2434.4	− 2528	−93.6	× 56 / 377	−13.9
6	91,007	2455.0	− 2552	−97	× 65 / 377	−16.7
7	91,008	2451.2	− 2567	−115.8	× 65 / 377	−20
8	91,009	2484.6	− 2586	−101.4	× 67 / 377	−18
Sum, rounded to a whole point						−83

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	93,214	2415.9	− 2436	−20.1	× 58 / 362	−3.2
4	93,215	2455.8	− 2485	−29.2	× 60 / 362	−4.8
5	93,216	2464.5	− 2528	−63.5	× 59 / 362	−10.3
6	93,217	2425.1	− 2552	−126.9	× 54 / 362	−18.9
7	93,218	2492.7	− 2567	−74.3	× 67 / 362	−13.8
8	93,219	2456.8	− 2586	−129.2	× 64 / 362	−22.8
Sum, rounded to a whole point						−74

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	93,114	2442.4	− 2436	6.4	× 51 / 353	0.9
4	93,115	2462.9	− 2485	−22.1	× 61 / 353	−3.8
5	93,116	2446.0	− 2528	−82	× 60 / 353	−13.9
6	93,117	2440.4	− 2552	−111.6	× 60 / 353	−19
7	93,118	2454.3	− 2567	−112.7	× 53 / 353	−16.9
8	93,119	2525.9	− 2586	−60.1	× 68 / 353	−11.6
Sum, rounded to a whole point						−64

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,997	2466.6	− 2436	30.6	× 62 / 335	5.7
4	92,998	2486.0	− 2485	1	× 53 / 335	0.2
5	92,999	2490.5	− 2528	−37.5	× 59 / 335	−6.6
6	93,000	2431.5	− 2552	−120.5	× 53 / 335	−19.1
7	93,001	2469.5	− 2567	−97.5	× 61 / 335	−17.8
8	93,002	2487.1	− 2586	−98.9	× 47 / 335	−13.9
Sum, rounded to a whole point						−51

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,729	2424.4	− 2436	−11.6	× 58 / 348	−1.9
4	92,730	2483.9	− 2485	−1.1	× 65 / 348	−0.2
5	92,731	2485.7	− 2528	−42.3	× 53 / 348	−6.4
6	92,732	2467.8	− 2552	−84.2	× 56 / 348	−13.5
7	92,733	2469.0	− 2567	−98	× 54 / 348	−15.2
8	92,734	2525.8	− 2586	−60.2	× 62 / 348	−10.7
Sum, rounded to a whole point						−48

2026 from sb_ca2026_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	92,333	2465.8	− 2436	29.8	× 68 / 356	5.7
4	92,334	2483.4	− 2485	−1.6	× 57 / 356	−0.3
5	92,335	2483.0	− 2528	−45	× 64 / 356	−8.1
6	92,336	2460.1	− 2552	−91.9	× 56 / 356	−14.5
7	92,337	2491.4	− 2567	−75.6	× 52 / 356	−11
8	92,338	2502.1	− 2586	−83.9	× 59 / 356	−13.9
Sum, rounded to a whole point						−42

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −47, −56, −58, −40, −43, −83, −74, −64, −51, −48, −42 → −55.1
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: 2 · 2017→2018: 18 · 2018→2019: 3 · 2019→2021: 40 · 2021→2022: 9 · 2022→2023: 10 · 2023→2024: 13 · 2024→2025: 3 · 2025→2026: 6 → average 11.3
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 11.3 × 2.66 = 30.1. Upper limit −25, lower limit −85.2.

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 — for a district, the total across its schools. From 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.

Chatom Union