Add 2-digit numbers by making tens 2

 is an exercise 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) Regroup the values: This problem provides two double-digit numbers in an addition problem, and asks the user to regroup the values by making tens. Adding2DigitNumbersByMakingTens2.png

Strategies
Knowledge of the associative properties can help, but are not necessary on this exercise.
 * 1) You can always compute the answer by adding the first two numbers and subtracting the third.