# Video: Interpreting and Solving Addition and Subtraction Word Problems

David and Jennifer were building houses out of blocks. David used 36 blocks. Jennifer used 51 blocks. How many blocks did they use? Will the answer be bigger or smaller than the numbers in the question? Do you need to add or subtract to find the answer? Find out how many blocks they need.

03:09

### Video Transcript

David and Jennifer were building houses out of blocks. David used 36 blocks. Jennifer used 51 blocks. How many blocks did they use? Then, we’re asked three questions. Will the answer be bigger or smaller than the numbers in the question? Do you need to add or subtract to find the answer? Find out how many blocks they need.

This problem asks us to find the total number of blocks that both David and Jennifer use altogether. And so the important information in the problem is the number 36 and the number 51. These are the amounts that both children use. Will the answer be bigger or smaller than the numbers in the question?

Let’s sketch a bar model to represent the problem. Here’s David’s amount of blocks. This bar represents the number of blocks that Jennifer uses. And the long bar underneath represents the total that we’re looking for. So we can see that the answer will be bigger than the numbers in the question because it is the sum of them.