Grade 1 Math · Level 3, Place Value to 120
Add a One-Digit Number Within 100
How the lesson starts: Add a One-Digit Number Within 100
Space gems
Blast off! Captain Nova collects shiny space gems. A full tube holds 10 gems. Loose gems float around. Let's add gems with Nova!
Add the ones
Nova has 42 gems. She finds 5 more. Add the ones. 2 ones and 5 ones make 7 ones. The tens stay 4 tens. 42 + 5 = 47!
Nova adds 3
73 + 3. Split 73 into 70 and 3. Add the ones. 3 + 3 = 6. The tens stay 7. So 73 + 3 = 76! Watch out! Don't add 3 to the tens. That would be 103.