Marcus has 731 books. he puts about the same number of books on each 9 shelves in his a bookcase. about how many books are in each shelf?

We need to divide the number of books, 731, by the number of shelves,  9

731 ÷ 9

In order to estimate the quotient, we will use compatible numbers.

731 is close to 720

Remember: Compatible numbers are numbers that are close in value to the actual numbers, and which make it easy to perform mental arithmetic.

Some examples of compatible numbers when doing division are 400 and 10, 36 and 6, 2400 and 12, and 64 and 8

720 and 9 are compatible because when doing this division (720 ÷9 ), we can quickly divide 72 by 9 to get 8 and put one zero at the end to get 80

720 ÷ 9 = 80  

About 80 books on each self

area = length x width

length = 2 x width

32 = 2 x width x width

32 = 2 x width^2

36 = width ^2  

width = 6

length = 12

area is 32

perimeter = 2 x 12 + 2 x 6 = 24 + 12 = 36

step-by-step explanation:

9 sandwiches per hour

step-by-step explanation:

when we have a rate, we want a 1 in the denominator

27/3 = 9

27 sandwiches/ 3 hours = 9 sandwiches/hour