Subtraction Within 20 Worksheet

Grade-1 subtraction facts within 20 — the not-yet-memorized band where strategies still show, with answer key.

1.8−32.8−83.8−54.8−15.5−46.9−37.6−48.7−59.10−610.6−611.7−212.10−313.8−414.10−415.6−116.2−217.9−518.9−419.10−120.4−421.3−322.7−423.7−324.5−3
Show answer key
1.8−352.8−803.8−534.8−175.5−416.9−367.6−428.7−529.10−6410.6−6011.7−2512.10−3713.8−4414.10−4615.6−1516.2−2017.9−5418.9−4519.10−1920.4−4021.3−3022.7−4323.7−3424.5−32
Customize this sheet

Teaching notes

The teens minus (13−5, 15−8) are where counting-back collapses; watch for students who 'count up' instead — that's the good strategy, name it and bless it.

Common Core: 1.OA.C.6

More sheets for Grade 1

Common Core alignment © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.