Students wrap the string from the problem on the left to the answer on the right, and then turn the Wrap-up over to see if they got it right. Use a stop watch to measure improvement and to see how fast they can really go. A string is already attached, making them easy to use and organize.Details:Orange2" x 1" x 6" (5.08cm x 2.54cm x 15.24cm)10 keys120 subtraction factsFor ages 6 and up