You've learned about classification word problems and comparison word problems. They are problems that sort and compare things. In some problems, we have to figur­e out the difference between two things. Although they are also comparison problems, they are also called difference problems. Now let's work on solv­ing difference word problems.

We've worked on problems that compare how much one thing is greater (larger) or less (smaller) than another.

The pink balloon flew 5 feet higher than the green balloon.

This problem compares the two balloons and tells about the difference.

The pink balloon flew higher, so it is the greatest number. The green balloon is a lesser number. The number 5 is the difference.

Look at the next problem.

Trevor has been to 8 states. Mary has been to 5 states. What is the difference in the number of states they have been to?

The problem asks about a difference, so we compare the numbers in the number family. Trevor has been to 8 states. Mary has been to 5 states. Trevor is the greatest number. He has been to more states than Mary. Mary is a lesser number. To find the difference, we subtract. Put the numbers you already know in the number family.

The difference equals 3. Trevor has been to 3 more states than Mary.

If the sentences tell of something having more or less, there is a difference number in the number family.