Giving Change When Payment Is Made with a Dime: The Difficulty of Tens and Ones

The purpose of this study was to investigate children's construction of 10s out of the Is they have already constructed. Ninety-eight children in Grades K-4 were individually interviewed in a store game in which they were the storekeepers and the interviewer was the customer buying candy. We tried to find out how children gave change when payment was made with a dime or a dime and a few pennies for purchases up to 9 cents. It was found that, for many younger children, a dime was something different from 10 pennies even though they could say with confidence that a dime was worth 10 cents. As the children grew older, their performance improved. Educational implications are discussed.