Number & Operations in Base Ten
1.NBT.B.2
1st Grade · Common Core Standards
Standard
Understand that the two digits of a two-digit number represent amounts of tens and ones. Understand the following as special cases:
Sub-standards
- 1.NBT.B.2.a — 10 can be thought of as a bundle of ten ones — called a "ten."
- 1.NBT.B.2.b — The numbers from 11 to 19 are composed of a ten and one, two, three, four, five, six, seven, eight, or nine ones.
- 1.NBT.B.2.c — The numbers 10, 20, 30, 40, 50, 60, 70, 80, 90 refer to one, two, three, four, five, six, seven, eight, or nine tens (and 0 ones).
Study materials
Study guide, practice problems, review, and practice test for this standard.
© Common Core State Standards Initiative. Used under CC BY 4.0. See thecorestandards.org for the official standards.