The Mac spreadsheet program, Numbers, is most often used by students to make graphs, but it’s also a great program to teach students how to create formulas to solve problems. As students troubleshoot their formulas, they gain a better understanding of the underlying math concepts and practice logical thinking. Third graders in Ms. Middleton’s class at Holladay have been learning about multiplication and division (SOL3.5) so today I showed them how to create their own calculators with Numbers. First I gave them a template that you can download by clicking here. I told them that these calculators were going to be a little different. Instead of giving the right answer, they would let you know if your answer is correct. So we made two columns for the factors or divisors and a column for people to write their answers. In the fourth column we wrote our formulas. I showed them how to write the first formula for checking multiplication and I let them write the division formulas on their own. Spreadsheet formulas are also helpful for reviewing map grids (SOL3.5e) since they use the same basic principle of identification. You can see all the formulas in the sample that comes with the template, but here’s the multiplication formula: =IF(D2=B2*C2,”Right!”,”Wrong!”). It checks if the answer in cell D2 equals the product of the numbers in B2 and C2, and let’s the user know if they are correct. The students wrote their own feedback messages (and some were rather creative 
After writing the formulas, students switched seats and tested each others’ calculators. Similar formulas can be written for almost every mathematical concept you teach. Go ahead and try it with your class!
