# Ten optional 8–12-minute extras

After-lesson extras for a local timetable, small group or home. One is enough. Use paper, speech/AAC, typed text, large/tactile pieces or a screen reader; no device, purchase or personal story is required. Day15/20 extras are **after the fresh check**.

| Day | Extra task | Low-material route | Check / next move |
| ---: | --- | --- | --- |
| 11 | Make `3/4+1/8=7/8` in two ways: eighths and a same-whole strip. | Fold/draw one strip. | Each representation has one whole and consistent part size. |
| 12 | Order the estimates for 4.75+2.60: 7, 8, 70. Explain which detect a decimal shift. | Spoken choices. | 7 or8 may be plausible coarse estimates;70 is not. Exact7.35. |
| 13 | Compute `1/2×1/4=1/8` by shaded overlap, then rotate partitions. | Eight-cell rectangle. | Reversing factors keeps the product. |
| 14 | Explain `1.5÷0.5=3` and `1.5×0.5=0.75` on one number line. | Paper tick marks. | Group count and scaling are different operations. |
| 15 | **After check:** find `3/5+1/10=7/10` and make a matching 0–1 sketch. | Ten equal marks. | No held-out check value is reused. |
| 16 | Start84 as7×12 and4×21; compare prime leaves. | Factor cards. | Both produce `2²×3×7`. |
| 17 | Evaluate `3³×2=54`, then factor54 back into primes. | Card list. | 3³=27, not9. |
| 18 | Show `90/150=9/15=3/5` by two valid common-factor steps. | Written fractions. | 90/150 and3/5 have the same value. |
| 19 | Link `49=7²` to `√49=7`, then contrast `7²` with `2⁷`. | Large number cards. | 7²=49;2⁷=128. |
| 20 | **After check:** factor120 and169; identify which is square and verify the root. | Paper tree/grid. | `120=2³×3×5`; `169=13²`, root13. |

These cards have not been classroom tested. Original SubjectNest extras © NeuroForgeIO Pty Ltd 2026, [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).