Common Core
2.NBT.B.9
8 lessons teach this standard. Every lesson is interactive, and every one prints as a worksheet with a separate answer key.
Grade 2 Math · Chapter 4 · Lesson 2
When the ones fill up, bundle them.
Grade 2 Math · Chapter 4 · Lesson 4
Say what you did and why it was allowed.
Grade 2 Math · Chapter 4 · Lesson 6
Not enough ones? Open a ten.
Grade 2 Math · Chapter 4 · Lesson 8
Add your answer back and see if you return.
Grade 2 Math · Chapter 4 · Lesson 11
Ones under ones. Add the ones first.
Grade 2 Math · Chapter 4 · Lesson 12
Column Subtraction, Written Out
Top digit too small? Borrow a ten.
Grade 2 Math · Chapter 5 · Lesson 5
Not enough tens? Open a hundred.
Grade 2 Math · Chapter 5 · Lesson 6
The hardest case, taken slowly.