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
+ 6
3
= 32   b)  63
 3
= 60
 3
+ 3
3
= 21
 
c)  128
  4
= 120
  4
+ 8
4
= 32   d)  186
  6
= 180
  6
+ 6
6
= 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.)
24.   Check your answer:  Multiply the quotient times the divisor.

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
3
3
= 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)   7
5
 =  1 2
5
  b)   26
 3
 =  8 2
3
  c)   23
 9
 =  2 5
9
  d)   31
 8
 =  3 7
8
 
e)   46
 7
 =  6 4
7
  f)   39
 4
 =  9 3
4
  g)   65
12
 =  5  5
12
  h)   53
 6
 =  8 5
6

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

Return to the previous Section.

Section 1 of this Lesson

 Table of Contents


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