Skill 6C
Using a Number Line: Find Missing Numbers to 50

Using a number line is a helpful tool when learning how to add and subtract.  Many teachers tape number lines to the top of their students' desks.  Number lines do a very good job in teaching the actual meaning and value of numbers. 

Each number line is missing one number.
What is the missing number?

12

14

     
     

30

31

     
     

48

49