Much of the math we do as adults involves making estimates. We are not born with the ability to make fairly accurate and reasonable estimates. Children need to have lots of experiences with making estimates.
Find a small box with a lid. Ask your child to guess how many pennies, cheerios, paperclips, etc. the box will hold. Whatever the guess, be it reasonable or not, have the child write the estimate down. Never comment negatively or positively on the estimate. I usually respond, “Okay”. A negative response to their estimate will lead to an unwillingness on the part of the child to make any more estimates.
Then fill the box and count to find out how many it did hold. Next time keep the same box but fill it with something different. Will this change the estimate? For instance, if you used Cheerios the first time you filled the box, and this time you are using marbles, will the estimate and count change? Can you get as many marbles in the box as you did Cheerios? Why or why not?
Do this many times and record your estimates and actual counts. The more your child does it, the better their estimates will become. He/she will probably also begin to notice that the smaller the objects, the more will fit in; the bigger the objects, the fewer that will fit in. Use all shapes and sizes of boxes and continue to make estimates and count.
When the french fries arrive from McDonald’s, have your child make an estimate and then count and eat to find out. Estimate coins in Dad’s pockets (number and value), houses on the block, days till the next birthday, meals you eat in a month, etc.
Here’s one of my favorite estimating activities:
How Many Shoes?
Make an estimate (smart guess) of how many shoes you think you will find in your home. ________________
Count the shoes in your home.
Your shoes _______________
Your Mom’s shoes ______________
Your Dad’s shoes _______________
Your brothers’ shoes ____________
Your sisters’ shoes ______________
Other shoes _________________
Total number of shoes _______________
How many pairs of shoes are in your home? ____________________
Are there more shoes or more pairs of shoes? ___________________
How many shoes do not have a matching one? _________________
How many shoes are in your closet? ___________________
Arrange your shoes in pairs. How many pairs? __________________
Are there more shoes or more feet in your home? ___________________
