My favorite tool to help children learn place value concepts is a plastic Unifix tray showing the 100s, 10s and 1s places.
First, children can see how adding 3 (ones) and 5 (ones) = 8 ones. Then add 8+1 more = 9. Only 9 ones can fit in the 1s place. What happens when you add 9+1 more? You have 10 ones.
EXCHANGING 10 ones for 1 ten
To do an exchange, I ask the child to hand me the 10 ones, and I hand them back one different color Unifix cube, and say that now they have a "new" ten, and to place this 1 ten in the 10s place on the tray. There are zero cubes left in the 1s place. 9+1 is 10. (1 ten and 0 ones) I also explain that this is the same as exchanging 10 pennies for a dime. Do a few more problems using math facts 5+5, 2+8, 6+4. Include math word problems such as: If you have 2 pennies, and I give you 8 more, how many will you have?
SUBSTITUTE FOR UNIFIX PLACE VALUE TRAY
You can make a place value tray out of paper like the example shown in Addition and Subtraction: Beyond Math Facts. (See a photo at the bottom of this post.) Or, use a plastic tray from a food item, like I did. This happens to be from a box of blintzes.
MORE WITH ADDITION FACTS
Once your student is comfortable with showing an exchange of 10 ones for a ten, ask them to add other math facts. Example: 9+5 (A "Magic 9" math fact from Two Plus Two Is Not Five) Have them show the 14 Unifix cubes on the tray.
Only 9 cubes fit in the 1s place, so an exchange is made. They give you 10 cubes. You give them 1 "new" ten to place in the 10s place. Four cubes remain in the 1s place. The number 14 is shown as 1 ten and 4 ones. Again, you can relate this to adding pennies. 9 pennies + 5 more pennies can be exchanged for 1 dime and 4 pennies. (See photo below.)
After children understand using place value for facts such 9+5=14, they ought to memorize the math fact. Two Plus Two Is Not Five is a workbook with all the tricks and tips to help your students learn and master addition and subtraction facts. Use this book along with Beyond Math Facts.
More posts will follow with subtraction and place value, on to the 100s place. Can't wait? Beyond Math Facts is available at many stores, and at online vendors, or you can buy directly from our Buy page.
