# What Measure Should I Use? {Mental Math Activity}

Here is a fun game to play in class. Tell students that you want to measure something and have them tell you which units you should use as a measure for problems involving both weight and linear measure.

For example, let’s say you wanted to measure the weight of a cow. Should you measure the cow in pounds or ounces?

What if you wanted to measure the weight of a mouse? Pounds or ounces?

What if you wanted to measure the length of a car? Should you use feet or inches? What about the weight of a car? Pounds or ounces?

Once you get students to think about these measurements and how they apply, start getting them to think about comparisons. For example, which do they think would weigh more, the car or the cow? Which weighs more, a hummingbird or a mouse?

Have your facts ready so that students can see the fun comparisons. For example, an average car weighs 4,000 pounds and an average cow weighs 1,500 pounds. Would four cows weigh more or less than one car?

These guessing games are just for fun but they increase your students’ number sense and give them a feeling for whether a measurement is correct or not.