2. Factor rainbows and arrays (4.OA.B.4)
Needs paper and colored pencils, grid paper for the arrays. Individual, usually.
Students list every factor pair of a number, write the factors in order, and connect each pair with an arc so the pairs make a rainbow, or they build each pair as an array on grid paper. It’s tidy practice, and the rainbow shows at a glance when a pair is missing. As usually run, though, it’s a solo drill with no problem behind it and no talk afterward, and you can’t see who reasoned it out. That misses four of the six, so treat it as practice and give the problems to something else.
The fix
- Keep it to ten minutes of practice, and let a problem like the zoo above do the rest.
- Pick numbers with lots of pairs, like 24 or 36, so a missing pair is worth hunting for.
No page for this one; the four misses are the fix.




