Number & Operations in Base Ten
1.NBT.C.4
1st Grade · Common Core Standards
Standard
Add within 100, including adding a two-digit number and a one-digit number, and adding a two-digit number and a multiple of 10, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Understand that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten.
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.