Master Math with a Rounding Race

By Brigid Del Carmen

This is a simple, fast game that you and your child can make together to help him master rounding with decimals. Find an opponent for your child, or use the clock. Either way, be prepared for a loud, exciting and competitive game!

What You Need:

• 6–7 sheets of paper or 3" x 5" note cards
• Scissors
• 2 black markers

What You Do:

1. Cut the paper into approximately 50 cards, or use 25 3" x 5" note cards, cut in half.
2. On each card, write dollar amounts in black marker. Use amounts from a penny, all the way up to $999.99. For example:
   • $38.14
   • $750.77
   • $10.75
3. Briefly review the process of rounding to the nearest dollar. Show your child how $38.14 rounds to $38.00. Here's how: the “ones” place comes just before the decimal, circle it (the 8) and look at the number to its right – 1 – which is less than 5. Therefore, the 8 stays the same and the 1 gets knocked down to 0. You have successfully rounded to $38.00. Have your child practice rounding with a few cards.
4. Now, it’s time to play! Have your fourth-grader challenge a sibling or friend. Both players sit next to each other facing you. Lay down a dollar card in front of the players. The first player to correctly round the number to the nearest dollar wins the card. Set a timer and play for 3 minutes. The player with the most cards at the end of 3 minutes wins the round. The winner of the game is the player with the best 3 out of 5 rounds.
5. If no one is available to “race” your child, challenge her to play against the clock. Set the timer for 3 minutes. Show her dollar cards one at a time and have her call out the rounded amount. See how many cards she can get in 3 minutes.
6. Challenge her to beat her record and reduce her time to 2 minutes, then 1 minute.

It’s always more fun if you supply “prizes” for the winner (and a consolation prize for the runner-up). But whatever way you crack it, this game will give kids another reward—the ability to approach rounding without fear.