Math
posted by Stone on .
Kathy has ribbons that have lengths of 7 inches, 10 inches, and 12 inches. Explain how she can use these ribbons to measure a length of 15 inches.

Place the 7inch ribbon on the 10inch ribbon. There will be 3 inches left over. Now put the 12inch ribbon at the end of the 3inch piece. Voila! You have 15 inches.