1.NBT.4

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.

Add multiples of 10

Add Multiples of 10

Add tens to a 2 digit number

Add Tens to a 2 Digit Number

Add ones to a 2 digit number

Add Ones to a 2 Digit Number