Students will learn how to find the area and perimeter of a rectangle with fractional side lengths.

Watch these Khan Academy videos:

Area of rectangles with fraction side lengths by Khan Academy

Next, give your students these challenges:

- 2018 Math Kangaroo Levels 5-6 Problem #19 by STEM4all

Ten red socks and ten blue socks are all mixed up in a dresser drawer. The twenty socks are exactly alike except for their color. The room is in pitch darkness and you want two matching socks. What is the smallest number of socks you must take out of the drawer in order to be certain that you have a pair that match? This puzzle comes from Gardner's *Entertaining Mathematical Puzzles.*

If students cannot figure it out, act out the problem as a class. For example, you could have a bag of twenty marbles, ten white and ten black. Have students draw from the bag until they get a matching pair. Running this experiment a few times, they will see maximum number of draws necessary is three. Then you can explain why.

Conclude by leading this investigation:

1-100 Composite Connector Challenge

by MathPickle

5.NF.B.4: Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.