If you have 8 dollars to but 42 cent postal stamps what is the greatest number of stamps?

To find the greatest number of 42-cent stamps you can buy with 8 dollars, first convert 8 dollars to cents, which is 800 cents. Then, divide 800 cents by 42 cents per stamp: 800 ÷ 42 ≈ 19.05. Since you can't purchase a fraction of a stamp, the greatest number of 42-cent stamps you can buy is 19.