Answer key: Area of rectangles (Grade K)
Companion answer key for the printable worksheet "Area of rectangles (Grade K)" — Common Core CCSS.MATH.K.G.A.1, Beginner difficulty. Use it to spot-check during the lesson or grade afterward.
Sample answers
| # | Question type | Sample answer |
|---|---|---|
| 1 | 24 + 45 | 69 |
| 2 | 40 + 32 | 72 |
| 3 | 47 + 36 | 83 |
| 4 | 25 + 33 | 58 |
| 5 | 22 + 19 | 41 |
| 6 | 50 + 49 | 99 |
| 7 | 11 + 35 | 46 |
| 8 | 31 + 49 | 80 |
How to grade this worksheet
This answer key is intentionally short — eight items or fewer — so you can spot-check during the lesson rather than waiting until the end. For Math worksheets at the beginner level, we recommend the following grading flow.
- Pencil-only spot check. Walk by every five minutes and circle (lightly) any item that looks off. Do not announce the score.
- Self-grade. When the student finishes, hand them this answer key and let them grade their own work in pen. Self-grading produces about 30% better retention than parent-grading at this age.
- Two-question debrief. Pick the two items they missed and ask: "Walk me through what you tried." Their explanation usually reveals whether it was a careless error or a genuine concept gap.
- Log the score. Note the score, the date, and the standard code (
CCSS.MATH.K.G.A.1) in your portfolio. Three data points across a month is enough to know if the standard is mastered.
If the student misses more than half of the items, do not reteach the same way. Switch modalities — manipulatives, a drawn diagram, a verbal walk-through — and revisit a fresh worksheet on the same standard the next morning.