Ralph says he can rewrite (4+5)+21 as 9+21. Do you agree ?why or why not?

Another type of subtraction equation is 16-b=7. explain how you would sole this equation then solve it.

Arestaurant offers delivery for their pizzas. the total cost the customer pays is the price of the pizzas, plus a delivery fee. one customer pays $23 to have 2 pizzas delivered. another customer pays $59 for 6 pizzas. how many pizzas are delivered to a customer who pays $86?

There are 10 chicks on ginger's farm .she has 2 chicks in one outdoor pen and 5 chicks in another. the rest of the chicks are in the barn. what is the fraction of total chicks in outdoor pens?