Add and subtract on the number line word problems

This first instance of the  exercise is in the Early Math Math Mission. This exercise teaches users to interpret addition and subtraction word problems using the number line as a visual.

Types of Problems
There are two types of problems in this exercise:
 * 1) Adding using the number line: this type of exercise asks users to interpret the addition word problem using the number line visual and choose the correct one.
 * 2) Subtracting using the number line: this type of exercise asks users to interpret the subtraction word problem using the number line visual and choose the correct one.

Strategies

 * 1) For these exercises, keep an eye out for key words in the problem and also numbers.
 * 2) Use the number line visual to help you and choose the correct one that matches the problem. Addsubwp2.png