Kelly bought a total of 40 pieces of squares and rectangular craft paper. She cut all the squares into 3 rectangles. She now has a total of 92 rectangles. How many pieces of rectangular craft paper did she buy? Ans: ___

1. Assume all pieces were rectangles and find the total number of rectangles in this scenario

If all $40$ pieces were rectangles, the total number of rectangles would be $40 \times 1 = 40$.

2. Find the difference between the actual number of rectangles and the assumed number

Difference in total rectangles $= 92 - 40 = 52$.

3. Find the difference in rectangles produced by one square compared to one rectangle

Each square produces $3$ rectangles, which is $3 - 1 = 2$ more rectangles than a piece of rectangular paper.

4. Calculate the number of squares and then the number of rectangles

Number of squares $= 52 \div 2 = 26$.
Number of rectangles $= 40 - 26 = 14$.