It helps you know what to multiply and the product when you subtracting and adding fractions.
A should be the right answer. Hope this helped!
Answer:
9
Step-by-step explanation:
3/7 multiplied by 21 = 3/7 x 21 = 9 = 3/7 x 21/1 = 63/7 = 9
Or if you can't do the math - Think of a pizza with 21 slices . Now cut this pizza into 7 equal parts. You will find that each part contains exactly 3 slices. Now, eat 3 of these parts. With three slices in each part, you ate 9 slices - which is three sevenths of 21.
