Ruby Drive 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	51,489	2405.3	− 2436	−30.7	× 48 / 222	−6.6
4	51,491	2456.1	− 2485	−28.9	× 60 / 222	−7.8
5	51,493	2460.8	− 2528	−67.2	× 60 / 222	−18.2
6	51,495	2452.7	− 2552	−99.3	× 54 / 222	−24.2
Sum, rounded to a whole point						−57

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	47,808	2433.8	− 2436	−2.2	× 50 / 229	−0.5
4	47,809	2444.1	− 2485	−40.9	× 54 / 229	−9.6
5	47,811	2491.5	− 2528	−36.5	× 60 / 229	−9.6
6	47,813	2494.8	− 2552	−57.2	× 65 / 229	−16.2
Sum, rounded to a whole point						−36

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,112	2429.2	− 2436	−6.8	× 53 / 224	−1.6
4	49,114	2448.3	− 2485	−36.7	× 53 / 224	−8.7
5	49,116	2455.2	− 2528	−72.8	× 59 / 224	−19.2
6	49,118	2477.3	− 2552	−74.7	× 59 / 224	−19.7
Sum, rounded to a whole point						−49

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,134	2427.0	− 2436	−9	× 45 / 221	−1.8
4	49,136	2447.3	− 2485	−37.7	× 58 / 221	−9.9
5	49,138	2466.3	− 2528	−61.7	× 56 / 221	−15.6
6	49,140	2463.9	− 2552	−88.1	× 62 / 221	−24.7
Sum, rounded to a whole point						−52

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,333	2432.4	− 2436	−3.6	× 40 / 209	−0.7
4	49,334	2448.2	− 2485	−36.8	× 52 / 209	−9.2
5	49,335	2458.8	− 2528	−69.2	× 62 / 209	−20.5
6	49,336	2481.6	− 2552	−70.4	× 55 / 209	−18.5
Sum, rounded to a whole point						−49

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,257	2402.4	− 2436	−33.6	× 34 / 175	−6.5
4	49,258	2406.2	− 2485	−78.8	× 47 / 175	−21.2
5	49,259	2444.7	− 2528	−83.3	× 45 / 175	−21.4
6	49,260	2452.6	− 2552	−99.4	× 49 / 175	−27.8
Sum, rounded to a whole point						−77

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,219	2396.4	− 2436	−39.6	× 52 / 175	−11.8
4	49,220	2451.6	− 2485	−33.4	× 34 / 175	−6.5
5	49,221	2449.6	− 2528	−78.4	× 50 / 175	−22.4
6	49,222	2465.9	− 2552	−86.1	× 39 / 175	−19.2
Sum, rounded to a whole point						−60

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	49,070	2402.4	− 2436	−33.6	× 55 / 197	−9.4
4	49,071	2442.5	− 2485	−42.5	× 56 / 197	−12.1
5	49,072	2481.6	− 2528	−46.4	× 34 / 197	−8
6	49,073	2466.3	− 2552	−85.7	× 52 / 197	−22.6
Sum, rounded to a whole point						−52

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	48,824	2407.8	− 2436	−28.2	× 47 / 185	−7.2
4	48,825	2448.5	− 2485	−36.5	× 51 / 185	−10.1
5	48,826	2470.5	− 2528	−57.5	× 52 / 185	−16.2
6	48,827	2476.2	− 2552	−75.8	× 35 / 185	−14.3
Sum, rounded to a whole point						−48

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −57, −36, −49, −52, −49, −77, −60, −52, −48 → −53.3
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 21 · 2016→2017: 13 · 2017→2018: 3 · 2018→2019: 3 · 2019→2022: 28 · 2022→2023: 17 · 2023→2024: 8 · 2024→2025: 4 → average 12.1
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 12.1 × 2.66 = 32.2. Upper limit −21.1, lower limit −85.5.

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.