THE MEANING OF DIVISION

PROBLEMS:  SECTION 2

Decomposing the dividend

15.  To find the quotient, decompose the dividend into obvious
15.  multiples of the divisor.

 a) 96 3 = 90 3 + 63 = 32 b) 63 3 = 60 3 + 33 = 21 c) 128  4 = 120  4 + 84 = 32 d) 186  6 = 180  6 + 66 = 31 e) 265  5 = 250  5 + 15 5 = 53

16.   Decompose the dividend into multiples of the divisor.  Find the
16.   quotient.

 a) 78 3 = 60  3 + 18  3 = 26 b) 92 4 = 80 4 + 12 4 = 23 c) 85 5 = 50 5 + 35 5 = 17 d) 91 7 = 70 7 + 21 7 = 13 e) 96 8 = 80 8 + 16 8 = 12 f) 56  4 = 40 4 + 16 4 = 14 g) 45 3 = 30 3 + 15 3 = 15 h) 84 6 = 60 6 + 24 6 = 14

17.   Decompose each dividend into multiples of the divisor, and find the
17.   quotient.  (Try the divisor into the first two digits of the dividend.)

 a) 237  3 = 210  3 + 27 3 = 79 b) 184  4 = 160  4 + 24 4 = 46 c) 185  5 = 150  5 + 35 5 = 37 d) 378  6 = 360  6 + 18 6 = 63 e) 441  7 = 63 f) 456  8 = 57 g) 105  7 = 15 h) 512  8 = 64 i) 432  9 = 450  9 − 18 9 = 48 j) 267  3 = 270  3 − 33 = 89 k) 136  4 = 34 l) 396  9 = 44 m) 385  5 = 77 n) 276  6 = 46

18.   Inexact division.  Write each quotient as a mixed number.

 a) 75 = 1 25 b) 26 3 = 8 23 c) 23 9 = 2 59 d) 31 8 = 3 78 e) 46 7 = 6 47 f) 39 4 = 9 34 g) 6512 = 5 512 h) 53 6 = 8 56

Can you do these mentally?  Decompose the dividend.

19.   How many 7's are there in 644?  92.   644 = 630 + 14.

20.   What number times 9 is 351?  39.   351 = 360 − 9.

21.   How many 8-inch boards could you cut from a piece that is 120
27.   inches?  15.   120 = 80 + 40.

22.   In 5 hours, Arlene was able to drive 315 miles.  How far did she
30.   travel in 1 hour?  That is, what was her speed?  Miles per hours.
27.   63 mph.   315 = 300 + 15.

23.   Helen took 6 exams, and the total of all her grades was 510.  What
32.   was her average grade?  85.   510 = 480 + 30.

24.   Joe borrowed \$408, and agreed to pay it back in one year in equal
32.   monthly payments.  How much will he pay each month?
32.   \$34.   408 = 360 + 48.  Divide each by 12.

25.   4 jackets that cost the same, together cost \$304.  How much did each
27.    one cost?  \$76.   304 = 280 + 24.

26.   You have \$425 from which you plan to make payments of \$35 each.
26.   How many payments will you be able to make?  12.
27.   425 = 350 + 70 + 5 = 12 × 35  + 5.

27.   A club wants to raise \$1400.  If it sells tickets at \$5 each, how many 27.   tickets must it sell?  280.   1400 = 1000 + 400.

28.   Divide \$882 equally among 9 people.  \$98 each.   882 = 900 − 18.

The problems following the next Lesson will include calculator problems.

Go on to the next Section.

or

Section 1 of this Lesson