Coin Shop

The big ideas

What the levels teach, in grown-up words.

• Each coin has a value. A penny is 1 cent, a nickel 5, a dime 10 and a quarter 25. The value is written on the coin, and it has nothing to do with the coin's size: a dime is smaller than a nickel but worth twice as much.
• Count coins by skip counting. Nickels count by fives, dimes by tens, quarters by twenty-fives. Start with the biggest coin and count on with the smaller ones.
• Many ways to make the same amount. Twenty-five cents can be a quarter, two dimes and a nickel, five nickels, or twenty-five pennies. The fewest coins come from using the biggest coins first.
• Change is counted up. If something costs 18 cents and you pay 25, count up from 18 to 25: the gap, 7 cents, is the change.
• One hundred cents make a dollar. Four quarters, ten dimes or twenty nickels each add up to a dollar. Prices over a dollar are written like $1.25.

Try it at home

Quick experiments that match the game.

1. Coin sort. Empty a jar of coins and sort them into pennies, nickels, dimes and quarters. Count each pile by ones, fives, tens and twenty-fives.
2. Play shop. Put price tags on a few toys and take turns being shopkeeper and customer. Pay with exact change, then pay with too much and work out the change.
3. Coin rubbing. Put paper over a coin and rub it with a crayon. Which coin has the biggest picture? Which is worth the most?
4. Dollar race. Each pick a coin type and see how many it takes to make a dollar. Quarters finish first!