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 pennies. 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 pennies are 1 cents and that a 100 pennies are equal to 1 dollar. Then tell your child 'we are going to make a dollar with pennies! Can you guess how many pennies we need to make a dollar?'
Start counting and lining up the pennies up to ten. Once you get to 10 start a new row of pennies. After you have two rows, write 10 on top of each row and put a plus sign in between and tell your child let's count how many pennies we have. "What's 10 + 10? 20. Now we have 20 cents does that make a dollar? why or why not? what should we do then? add more cents until we reach a 100." Every now and then stop and ask again "do we have enough?"
After each row of pennies write the number 10 on top and add by tens from the beginning. After you have 100 pennies emphasise that all of those pennies are equal to the 1 dollar bill.
You can 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 or the 1 dollar bill? You can give either one because they are equal! Which one do you think they would like you to give? and why? that's right, they wouldn't be too happy counting 100 pennies!!"
Go over this concept a couple of times on different days until your child completely understands the concept that 100 pennies make a dollar.