1 dollar bill
paper and pen
Show your child the dollar bill and ask him/her how much it is? If they don't know you can show the number 1 and tell them that it's a one dollar bill.
Next show the dimes. Ask them if they remember what the name of this coin is? And how much it's worth.
On a sheet of paper write down that dimes are 10 cents and that a 100 cents are equal to 1 dollar. Then tell your child 'we are going to make a dollar with dimes! Can you guess how many dimes we need to make a dollar? I don't know.. let's find out together!'
We get to count by 10's because a dime is 10 cents! Place a dime on the paper and put the number 10 on top of it. Next place the second dime and put the number 10 on top of that one. Draw the plus sign in between and ask your child what's 10 cents+10 cents. It's 20 cents, is that a dollar? why or why not? We need a 100 cents to make a dollar and we only have 20. What do we need to do? add another dime. Now let's count 10, 20, 30 do we have enough? Keep going until you reach a 100.
When you reach a 100 cents go back and count by 10's one more time together to check your work. Then you can ask how many dimes did we use to make one dollar? Let's count and see. 10 dimes make one dollar! If you still have the sheet with the pennies and nickels from the other day's exercise you can compare the 4 different ways to make a dollar. (the dollar bill, 100 pennies, the 20 nickels, and the 10 dimes!) Emphasize that all four ways are equal. You can use our earlier example and say something like, "If you went to the store and wanted to buy a candy bar for 1 dollar, which one can you give the 100 pennies, 20 nickels, 10 dimes or the 1 dollar bill? You can give any one of the choices because they are all equal! Which one do you think would be their 1st, 2nd, 3rd, and 4th choice. and why? First choice would be the dollar bill, then the dimes, then the nickels and last the pennies!"
Go over this concept a couple of times on different days until your child completely understands that dimes are 10 cents and that 10 dimes are equal to a one dollar bill.