Math 1 · Lesson 3 · Step One · part 5 of 9
You will be multiplying fractions
Because "divide by 2" becomes "multiply by 1 2 ," you need to multiply fractions comfortably.
You will be multiplying fractions
Because "divide by 2" becomes "multiply by 12," you need to multiply fractions comfortably. It is the friendly one: multiply the tops, multiply the bottoms, then simplify.
The move
45 × 38 = 1240 = 310.
A whole number rides as itself over 1: 6 = 61. A mixed number turns improper first: 212 = 52.
The check that matters
A number times its reciprocal is 1: 23 × 32 = 66 = 1.
That is the whole point of the reciprocal, and it is why dividing by 23 is the same as multiplying by 32.