Rio Elementary: 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	103,871	2393.5	− 2436	−42.5	× 580 / 3121	−7.9
4	103,874	2422.3	− 2485	−62.7	× 531 / 3121	−10.7
5	103,875	2444.7	− 2528	−83.3	× 460 / 3121	−12.3
6	103,878	2462.8	− 2552	−89.2	× 520 / 3121	−14.9
7	103,879	2475.4	− 2567	−91.6	× 543 / 3121	−15.9
8	103,882	2491.0	− 2586	−95	× 487 / 3121	−14.8
Sum, rounded to a whole point						−76

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	96,524	2406.0	− 2436	−30	× 557 / 3262	−5.1
4	96,526	2423.4	− 2485	−61.6	× 599 / 3262	−11.3
5	96,527	2449.1	− 2528	−78.9	× 544 / 3262	−13.2
6	96,530	2468.5	− 2552	−83.5	× 495 / 3262	−12.7
7	96,531	2486.5	− 2567	−80.5	× 520 / 3262	−12.8
8	96,534	2492.1	− 2586	−93.9	× 547 / 3262	−15.7
Sum, rounded to a whole point						−71

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	99,319	2412.0	− 2436	−24	× 573 / 3322	−4.1
4	99,321	2438.2	− 2485	−46.8	× 562 / 3322	−7.9
5	99,322	2453.8	− 2528	−74.2	× 607 / 3322	−13.6
6	99,324	2463.5	− 2552	−88.5	× 547 / 3322	−14.6
7	99,326	2477.6	− 2567	−89.4	× 508 / 3322	−13.7
8	99,328	2512.6	− 2586	−73.4	× 525 / 3322	−11.6
Sum, rounded to a whole point						−65

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	99,478	2414.1	− 2436	−21.9	× 546 / 3347	−3.6
4	99,479	2445.7	− 2485	−39.3	× 573 / 3347	−6.7
5	99,482	2458.2	− 2528	−69.8	× 571 / 3347	−11.9
6	99,483	2463.0	− 2552	−89	× 594 / 3347	−15.8
7	99,486	2478.4	− 2567	−88.6	× 537 / 3347	−14.2
8	99,487	2497.7	− 2586	−88.3	× 526 / 3347	−13.9
Sum, rounded to a whole point						−66

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	100,141	2416.2	− 2436	−19.8	× 597 / 3459	−3.4
4	100,142	2446.8	− 2485	−38.2	× 551 / 3459	−6.1
5	100,143	2466.1	− 2528	−61.9	× 604 / 3459	−10.8
6	100,144	2477.8	− 2552	−74.2	× 568 / 3459	−12.2
7	100,145	2473.1	− 2567	−93.9	× 598 / 3459	−16.2
8	100,146	2497.0	− 2586	−89	× 541 / 3459	−13.9
Sum, rounded to a whole point						−63

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	98,000	2364.6	− 2436	−71.4	× 507 / 3293	−11
4	98,001	2401.7	− 2485	−83.3	× 533 / 3293	−13.5
5	98,002	2424.9	− 2528	−103.1	× 591 / 3293	−18.5
6	98,003	2442.3	− 2552	−109.7	× 556 / 3293	−18.5
7	98,004	2472.2	− 2567	−94.8	× 578 / 3293	−16.6
8	98,005	2473.3	− 2586	−112.7	× 528 / 3293	−18.1
Sum, rounded to a whole point						−96

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	100,362	2396.5	− 2436	−39.5	× 523 / 3333	−6.2
4	100,363	2422.1	− 2485	−62.9	× 519 / 3333	−9.8
5	100,364	2445.6	− 2528	−82.4	× 556 / 3333	−13.7
6	100,365	2456.9	− 2552	−95.1	× 585 / 3333	−16.7
7	100,366	2482.2	− 2567	−84.8	× 560 / 3333	−14.2
8	100,367	2481.6	− 2586	−104.4	× 590 / 3333	−18.5
Sum, rounded to a whole point						−79

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	100,198	2408.6	− 2436	−27.4	× 548 / 3356	−4.5
4	100,199	2434.1	− 2485	−50.9	× 535 / 3356	−8.1
5	100,200	2455.5	− 2528	−72.5	× 525 / 3356	−11.3
6	100,201	2459.1	− 2552	−92.9	× 572 / 3356	−15.8
7	100,202	2469.1	− 2567	−97.9	× 607 / 3356	−17.7
8	100,203	2485.2	− 2586	−100.8	× 569 / 3356	−17.1
Sum, rounded to a whole point						−75

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	100,079	2401.9	− 2436	−34.1	× 547 / 3337	−5.6
4	100,080	2441.3	− 2485	−43.7	× 551 / 3337	−7.2
5	100,081	2458.1	− 2528	−69.9	× 551 / 3337	−11.5
6	100,082	2460.2	− 2552	−91.8	× 529 / 3337	−14.6
7	100,083	2470.1	− 2567	−96.9	× 567 / 3337	−16.5
8	100,084	2471.1	− 2586	−114.9	× 592 / 3337	−20.4
Sum, rounded to a whole point						−76

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	99,785	2391.4	− 2436	−44.6	× 544 / 3310	−7.3
4	99,786	2436.9	− 2485	−48.1	× 551 / 3310	−8
5	99,787	2456.5	− 2528	−71.5	× 571 / 3310	−12.3
6	99,788	2461.9	− 2552	−90.1	× 557 / 3310	−15.2
7	99,789	2473.6	− 2567	−93.4	× 534 / 3310	−15.1
8	99,790	2495.2	− 2586	−90.8	× 553 / 3310	−15.2
Sum, rounded to a whole point						−73

2026 from sb_ca2026_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	99,448	2401.5	− 2436	−34.5	× 540 / 3275	−5.7
4	99,449	2426.7	− 2485	−58.3	× 539 / 3275	−9.6
5	99,450	2456.7	− 2528	−71.3	× 560 / 3275	−12.2
6	99,451	2475.5	− 2552	−76.5	× 556 / 3275	−13
7	99,452	2483.7	− 2567	−83.3	× 552 / 3275	−14
8	99,453	2489.9	− 2586	−96.1	× 528 / 3275	−15.5
Sum, rounded to a whole point						−70

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −76, −71, −65, −66, −63, −96, −79, −75, −76, −73, −70 → −73.6
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 5 · 2016→2017: 6 · 2017→2018: 1 · 2018→2019: 3 · 2019→2021: 33 · 2021→2022: 17 · 2022→2023: 4 · 2023→2024: 1 · 2024→2025: 3 · 2025→2026: 3 → average 7.6
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 7.6 × 2.66 = 20.2. Upper limit −53.4, lower limit −93.8.

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.

Rio Elementary