# Proportional Thinking (Number Sense Series, Part 3)

By Mathnasium | May 14, 2018

“If the world was the size of a basketball, my house would be as big as a flea’s flea!”

This is an example of how a seven year old once expressed proportional thinking to Mathnasium’s Co-Founder and Chief Education Officer, Larry Martinek. Of course, this seven year old didn’t know he was expressing proportional thinking at the time, he just knew it was fun to think about familiar objects changing size in relation to other familiar objects!

This demonstration of a “sense of scale,” placing a home in proportion to a basketball-sized world, was setup by verbal questions that involved proportional thinking.  Asking questions with your kids can help them develop strong mental math skills.  Let’s take a look at some more examples.

Imagine an amusement park filled with all sorts of rides, clowns, arcades, food—the works! Now along with that, place a carousel, ten times bigger than every other attraction, somewhere into this amusement park. It would completely stand out because it would be out of proportion.

Understanding these concepts involves a working knowledge of Proportional Thinking.

Proportional Thinking is “thinking according to amount.” The amount of one thing can be adjusted according to the amount of something else. Many kids have a difficult time visualizing proportionally. This is because they need to be able to develop a mental image of a sense of proportion—“a sense of scale.“