Money provides a perfect, authentic opportunity to explore mathematics. Not only does each coin and bill have an assigned value, currency also makes a great math manipulative for sorting, counting, comparing, measuring, adding, subtracting, multiplying, dividing, and eventually using fractions, decimals, percentages, and more.
1. Sorting with Coins
With the youngest* learners, you can start by sorting. Ask children to sort coins into piles. Once they are done, ask them about their method. Did they sort by color, by size, by picture, by numbers, or something else? They may create one pile of silver coins and one of copper coins. Ask them if they can further classify the silver coins. See if they can put the coins in size order. Ask them which coin they think is worth the most and which is worth the least and why. This is a good lead-in to identifying the names and values of each coin.
2. Counting with Coins
Ask children to help you count your spare change to put into rolls. If you give them some of the money for assisting, they may be even more eager to help. Have younger children create piles of 5 or 10 coins if they are not yet able to count past 10. Show kids how you can skip count the piles to reach the number you need for your roll.
3. Comparing with Coins
Create stacks of pennies, nickels, dimes, and quarters to equal one dollar. Ask children which group is bigger, which is smaller, and why. Ask whether they would prefer four quarters, ten dimes, 20 nickles, or 100 pennies. Help them figure out how much each of these is worth and then ask again!
4. Measuring with Coins
Measure across a table with coins. How many quarters across is your table? How many dimes? Nickles? Pennies? Why is this? Does a coin’s diameter correspond to its value?
5. Adding and Subtracting with Coins
Coins make easy manipulatives for adding and subtracting. Just take two pennies and three nickles and then sweep them together. How many coins in all? Now, take away the three nickles from the five coins and how many pennies are left? Older children can use the true currency value in their adding. Make the learning even more authentic by playing store. This fabulous hat costs just three dollars. Count out three dollars and it is yours! I have two dollars, how many more dollars do we need? (Look at that, you just did algebra!)
6. Adding and Subtracting with Regrouping
Pennies, dimes, dollar bills, and ten dollar bills make perfect stand-ins for place value. When learning regrouping, explain that you want to have as few pieces of currency as possible. So, if you have ten pennies, you regroup them into a dime, ten dimes becomes a dollar bill, and so on. So, adding 16 plus 16 is like adding six pennies plus six pennies, regrouping ten into a dime with two left over, and then adding your three dimes. For an illustrated example, see how we used currency to learn regrouping. When subtracting, you’ll need to “break” your money into smaller units to complete the equation. Play store again: I want to buy this ball and the bat. The ball costs 28 cents and the bat costs 75 cents. How much do I need to get both? This magical wand costs $9.58 but I only have a ten dollar bill. How much change will I get?
7. Multiplication and Division with Coins
Group pennies to practice multiplication and division. For example, seven groups of four pennies is 28 pennies. You can also use the value of the coins to reinforce these concepts. If it takes four quarters to equal one dollar, how many quarters will equal seven dollars? 4 quarters x 7 = 28. Go back to your coin rolls. Children who can multiply can now tell you how many coins of each denomination you need to fill each roll.
Kids who use money in math become more familiar with both topics. Money provides a real-life incentive for learning mathematics and mathematics helps them keep track of finances as they get older. Introducing both together at an early age helps children make connections and develop confidence with two essential parts of life.
*Be aware that coins can be a choking hazard to very young children.