About this worksheet
Twenty number sentences to solve in your head by thinking in hundreds and tens. Some add hundreds to hundreds (300 + 400), some add tens or hundreds to a three-digit number (420 + 30, 245 + 300), and a few add tens to tens and cross 100 (70 + 60, 80 + 80).
The ones that cross 100 are the interesting ones. 380 + 20 lands exactly on 400, and a child who sees that without writing anything down has a real feel for place value.
What students will practice
- Add hundreds to hundreds mentally
- Add tens to a three-digit number
- Add tens that cross 100
Details
- Grade level
- Grade 2
- Subject
- Math · Addition
- Standard
- CCSS 2.NBT.B.7
- Pages
- 1
- Format
- PDF · US Letter and A4 included
- License
- Free for classroom use · Attribution appreciated
- Last updated
- October 13, 2026
