6. Ten children went to soccer practice. 1/2 decided to go for pizza afterwards. It takes 3 children to eat 1 pizza. How many pizzas did they eat?
This is a multi-part problem. First we have to find 1/2 of the children. "of" means multiply, so we multiply 10x1/2. The 2 in the bottom will cancel with the 10 on the top, and since 2 goes into 10 5 times, 1/2 of 10 children are 5 children.
Now that we know how many children we have we can find out how many pizzas we need. It takes 3 children to eat 1 pizza. That gives us 3 children per pizza. Since we have the word "per' in the units, the 3 children per pizza is a rate. Since the word "pizza" comes after the word "per", the pizzas are the base. In the A = RB types of problems, if we need to find the base, the base is what we need to multiply times the rate to get the amount. The amount in this case is the 5 children, so we need to find out what we need to multiply times 3 children per pizza to get 5 children. To find out what you need to multiply, divide. This is the B = A/R type of problem.
5 children / 3 children per pizza = 5/3 pizzas.
If we turn this into a mixed number it will give us 1 and 2/3 pizzas.