It is important that children understand a variety of ways to use place value to compute double-digit addition equations. This lesson shows how to add within 100 using a two-digit number and a one-digit number, as well as adding a two-digit number and a multiple of 10, using a hundred chart. This strategy is based on place value, properties of operations, and/or the relationship between addition and subtraction. Building an understanding
that in adding two-digit numbers, one adds tens and tens, ones and ones; and sometimes it is necessary to compose a ten. Using the hundred chart allows for visual processing of place value and encourages kinesthetic learns by being able to touch and move around the number chart and feel what changes in place value are happening.
