Question

Mrs.green needs to store 21 math books on a shelf during school vacation. Each math book is 2.4 centimeters thick. If Mrs.Green stacks the math books on top of each other, how tall does the shelf have to be?

Answer 1

each book is 2.4cm thick; that means if you're stacking books on top of each other, that is, on their sides, each book will be 2.4 cm tall. multiply the length of each book (2.4cm) by 21 to figure out how tall 21 books together will be. 2.4 x 21 = 50.4. the shelf needs to be at least 50.4cm tall.