Redwood Coast Montessori: 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.

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	12,911	2450.9	− 2436	14.9	× 14 / 73	2.9
5	12,913	2482.9	− 2528	−45.1	× 15 / 73	−9.3
6	12,914	2480.2	− 2552	−71.8	× 13 / 73	−12.8
7	12,915	2586.6	− 2567	19.6	× 17 / 73	4.6
8	12,916	2589.5	− 2586	3.5	× 14 / 73	0.7
Sum, rounded to a whole point						−14

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	12,746	2435.4	− 2436	−0.6	× 14 / 85	−0.1
4	12,747	2478.5	− 2485	−6.5	× 14 / 85	−1.1
5	12,748	2506.2	− 2528	−21.8	× 14 / 85	−3.6
7	12,750	2579.0	− 2567	12	× 24 / 85	3.4
8	12,751	2586.2	− 2586	0.2	× 19 / 85	0
Sum, rounded to a whole point						−1

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	12,943	2407.4	− 2436	−28.6	× 12 / 87	−3.9
4	12,944	2462.9	− 2485	−22.1	× 14 / 87	−3.6
5	12,945	2483.6	− 2528	−44.4	× 14 / 87	−7.1
6	12,946	2505.0	− 2552	−47	× 26 / 87	−14
8	12,948	2590.1	− 2586	4.1	× 21 / 87	1
Sum, rounded to a whole point						−28

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	12,920	2444.9	− 2436	8.9	× 15 / 88	1.5
4	12,921	2480.5	− 2485	−4.5	× 12 / 88	−0.6
5	12,922	2522.5	− 2528	−5.5	× 14 / 88	−0.9
6	12,923	2514.4	− 2552	−37.6	× 24 / 88	−10.3
7	12,924	2576.5	− 2567	9.5	× 23 / 88	2.5
Sum, rounded to a whole point						−8

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	12,877	2432.6	− 2436	−3.4	× 12 / 103	−0.4
4	12,878	2455.1	− 2485	−29.9	× 15 / 103	−4.4
5	12,879	2504.4	− 2528	−23.6	× 13 / 103	−3
6	12,880	2546.1	− 2552	−5.9	× 19 / 103	−1.1
7	12,881	2568.4	− 2567	1.4	× 22 / 103	0.3
8	12,882	2562.9	− 2586	−23.1	× 22 / 103	−4.9
Sum, rounded to a whole point						−13

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	12,859	2425.3	− 2436	−10.7	× 15 / 117	−1.4
4	12,860	2429.8	− 2485	−55.2	× 12 / 117	−5.7
5	12,861	2512.6	− 2528	−15.4	× 14 / 117	−1.8
6	12,862	2508.0	− 2552	−44	× 17 / 117	−6.4
7	12,863	2563.3	− 2567	−3.7	× 21 / 117	−0.7
8	12,864	2583.1	− 2586	−2.9	× 24 / 117	−0.6
11	12,865	2595.3	− 2628	−32.7	× 14 / 117	−3.9
Sum, rounded to a whole point						−20

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −14, −1, −28, −8, −13, −20 → −14
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2019→2021: 13 · 2021→2022: 27 · 2022→2023: 20 · 2023→2024: 5 · 2024→2025: 7 → average 14.4
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 14.4 × 2.66 = 38.3. Upper limit 24.3, lower limit −52.3.

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 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.