Multiplying mixed numbers
Episode 2 of 4
Perimeter of three squares
The question
A square has sides 5 3/10 cm each. What is the perimeter of a rectangle that is made up of 3 such squares in a row? Express the answer as a mixed number.
Try it first, then show the answerHide the answer
Answer
42 2/5 cm
The big idea
Perimeter is only the outside. Walk around the shape: 8 sides, not 12. Then turn the extra tenths into wholes.