Common Core
1.NBT.B.2
5 lessons teach this standard. Every lesson is interactive, and every one prints as a worksheet with a separate answer key.
Grade 1 Math · Chapter 4 · Lesson 4
The tens digit always comes first.
Grade 1 Math · Chapter 7 · Lesson 2
Show any number to 40 as tens and ones.
Grade 1 Math · Chapter 7 · Lesson 4
The same number can be built in more than one way.
Grade 1 Math · Chapter 10 · Lesson 3
Tens and ones work the same all the way to 100.
Grade 1 Math · Chapter 10 · Lesson 10
Look back at everything you learned this year.