Millbrae 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	83,210	2458.1	− 2436	22.1	× 274 / 1615	3.7
4	83,212	2507.1	− 2485	22.1	× 248 / 1615	3.4
5	83,214	2518.1	− 2528	−9.9	× 249 / 1615	−1.5
6	83,217	2547.2	− 2552	−4.8	× 255 / 1615	−0.8
7	83,218	2572.1	− 2567	5.1	× 294 / 1615	0.9
8	83,220	2614.1	− 2586	28.1	× 295 / 1615	5.1
Sum, rounded to a whole point						11

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	77,163	2469.2	− 2436	33.2	× 245 / 1614	5
4	77,165	2510.6	− 2485	25.6	× 276 / 1614	4.4
5	77,166	2533.6	− 2528	5.6	× 252 / 1614	0.9
6	77,168	2553.7	− 2552	1.7	× 272 / 1614	0.3
7	77,171	2588.6	− 2567	21.6	× 263 / 1614	3.5
8	77,173	2611.4	− 2586	25.4	× 306 / 1614	4.8
Sum, rounded to a whole point						19

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,265	2473.7	− 2436	37.7	× 254 / 1568	6.1
4	79,267	2505.4	− 2485	20.4	× 251 / 1568	3.3
5	79,269	2535.8	− 2528	7.8	× 279 / 1568	1.4
6	79,272	2542.6	− 2552	−9.4	× 265 / 1568	−1.6
7	79,274	2605.1	− 2567	38.1	× 259 / 1568	6.3
8	79,276	2612.3	− 2586	26.3	× 260 / 1568	4.4
Sum, rounded to a whole point						20

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,409	2478.1	− 2436	42.1	× 247 / 1612	6.5
4	79,410	2517.0	− 2485	32	× 272 / 1612	5.4
5	79,413	2525.2	− 2528	−2.8	× 253 / 1612	−0.4
6	79,414	2544.3	− 2552	−7.7	× 289 / 1612	−1.4
7	79,417	2578.7	− 2567	11.7	× 271 / 1612	2
8	79,418	2614.8	− 2586	28.8	× 280 / 1612	5
Sum, rounded to a whole point						17

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,939	2472.4	− 2436	36.4	× 249 / 1573	5.8
4	79,940	2513.1	− 2485	28.1	× 232 / 1573	4.1
5	79,941	2544.6	− 2528	16.6	× 273 / 1573	2.9
6	79,942	2552.7	− 2552	0.7	× 256 / 1573	0.1
7	79,943	2565.6	− 2567	−1.4	× 290 / 1573	−0.3
8	79,944	2590.7	− 2586	4.7	× 273 / 1573	0.8
Sum, rounded to a whole point						13

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	78,394	2468.5	− 2436	32.5	× 213 / 1355	5.1
4	78,395	2498.6	− 2485	13.6	× 249 / 1355	2.5
5	78,396	2534.4	− 2528	6.4	× 236 / 1355	1.1
6	78,397	2541.9	− 2552	−10.1	× 197 / 1355	−1.5
7	78,398	2584.5	− 2567	17.5	× 236 / 1355	3
8	78,399	2597.8	− 2586	11.8	× 224 / 1355	2
Sum, rounded to a whole point						12

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,197	2477.3	− 2436	41.3	× 235 / 1407	6.9
4	80,198	2515.5	− 2485	30.5	× 226 / 1407	4.9
5	80,199	2532.8	− 2528	4.8	× 246 / 1407	0.8
6	80,200	2543.6	− 2552	−8.4	× 228 / 1407	−1.4
7	80,201	2582.5	− 2567	15.5	× 221 / 1407	2.4
8	80,202	2592.3	− 2586	6.3	× 251 / 1407	1.1
Sum, rounded to a whole point						15

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,161	2469.9	− 2436	33.9	× 212 / 1384	5.2
4	80,162	2525.1	− 2485	40.1	× 247 / 1384	7.2
5	80,163	2553.6	− 2528	25.6	× 223 / 1384	4.1
6	80,164	2541.9	− 2552	−10.1	× 238 / 1384	−1.7
7	80,165	2596.0	− 2567	29	× 232 / 1384	4.9
8	80,166	2584.6	− 2586	−1.4	× 232 / 1384	−0.2
Sum, rounded to a whole point						19

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	80,187	2479.5	− 2436	43.5	× 217 / 1402	6.7
4	80,188	2510.0	− 2485	25	× 215 / 1402	3.8
5	80,189	2544.0	− 2528	16	× 249 / 1402	2.8
6	80,190	2574.4	− 2552	22.4	× 235 / 1402	3.8
7	80,191	2578.0	− 2567	11	× 252 / 1402	2
8	80,192	2605.8	− 2586	19.8	× 234 / 1402	3.3
Sum, rounded to a whole point						22

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	79,853	2475.8	− 2436	39.8	× 229 / 1433	6.4
4	79,854	2529.3	− 2485	44.3	× 232 / 1433	7.2
5	79,855	2538.7	− 2528	10.7	× 222 / 1433	1.7
6	79,856	2578.3	− 2552	26.3	× 258 / 1433	4.7
7	79,857	2599.7	− 2567	32.7	× 233 / 1433	5.3
8	79,858	2611.3	− 2586	25.3	× 259 / 1433	4.6
Sum, rounded to a whole point						30

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. 11, 19, 20, 17, 13, 12, 15, 19, 22, 30 → 17.8
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 8 · 2016→2017: 1 · 2017→2018: 3 · 2018→2019: 4 · 2019→2021: 1 · 2021→2022: 3 · 2022→2023: 4 · 2023→2024: 3 · 2024→2025: 8 → average 3.9
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 3.9 × 2.66 = 10.4. Upper limit 28.2, lower limit 7.4.

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.