Add 2-digit numbers by making tens

The topic  is a topic under the Early Math Math Mission. This exercise practices some of the basic ideas of associativity to help with regrouping and finding sums.

Types of Problems
There is one type of problem in this exercise:


 * 1) Split the number to find the sum: This problem provides an initial addition problem that can be conveniently split up into a different sum. The problem guides the student through how to split a number to make it easier to calculate. The student is expected to provide the correct answer at each step and write it in the boxes.Augotl2-1.png

Strategies
Knowledge of the associative properties can help, but are not necessary on this exercise. In fact, the exercise can be seen as a possible motivation for understanding the associative property of addition.
 * 1)  The calculation performed in this problem is the fashion that many "human calculators" use to add numbers mentally.
 * 2) The answers to the first two prompts will be the same number. The next slot will be a multiple of ten, and final slot is always the answer.
 * 3) Research has not been able to find the difference between this problem and Addition using groups of 10: Level 1 yet. At the very least they are intimately related.