This is a digital matching and puzzle assembling activity on calculating percent of a number. On the first slide there are given a total of 12 challenging problems numbered with 1a,2a,3a,4a,1b,2b,3b,4b,1c,2c,3c, and 4c. For each problem, students have to find a sum of type a% of b + c% of d calculating the percentages. On the second slide the answers of the problems are given in random order. Students have to type the number of each problem next to its answer in the empty box provided. There