PROBLEMS

Do the problem yourself first!

11.  Calculate the following.

 11.  a) 3 sevenths + 2 sevenths = 5 sevenths b) 37 + 27 = 57
 11. c) 37 − 27 = 17 d) 1516 − 5 16 = 1016 = 58
 11.  e) 35 + 15 + 45 = 1 35 f) 24 + 14 + 34 = 1½ g) 1015 + 8 15 − 4 15 = 1415

12.  Choose the LCM of denominators to calculate the following.

 12.   a) 23 + 16 = 56 b) 5 12 + 14 = 23 c) 12 + 5 32 = 2132
 12.   d) 35 − 2 15 = 7 15 e) 38 − 7 32 = 5 32 f) 1516 − 34 = 3 16

13.  Choose the LCM of denominators to calculate the following.

 13.   a) 56 + 59 = 1 7 18 b) 34 + 56 = 1 7 12 c) 56 + 38 = 1 5 24
 13.   d) 1115 − 7 10 = 1 30 e) 78 − 5 12 = 1124 f) 89 − 5 12 = 1736

14.  Calculate the following.

 14.   a) 12 + 13 = 56 b) 38 + 25 = 3140 c) 79 + 7 10 = = 1 4390
 14.   d) 27 − 15 = 3 35 e) 34 − 23 = 1 12 f) 78 − 59 = 2372

 15.   a) 12 + 13 + 14 = 1 1 12 b) 12 + 34 + 45 = 2 1 20 c) 12 + 56 − 34 = 7 12

16.  Mental calculation.

 16.   a) 12 + 14 = 34 b) 12 + 18 = 58 c) 12 + 2 10 = 7 10
 16.   d) 12 + 34 = 1¼ e) 12 + 1 16 = 9 16 f) 12 + 5 12 = 1112

17.  Mental calculation.

 17.   a) 12 + 14 + 18 = 78 b) 12 + 38 + 5 16 = 1 3 16 c) 14 + 58 + 3 16 = 1 1 16

18.  What number must you add to each of the following to make 1?

18   Compare Example 8.

 a) 12 + 13 + 16 = 1
 b) 25 + 16 + 1330 = 1
 c) 18 + 34 + 18 = 1

19.   Three candidates were running for office.  One of them got half the
10.   vote.  Another got two fifths of the vote.  What fraction did the

 third candidate get? 1 10 .

10.   On the first day, Claude read half the book. On the second day, he
10.   read three eighths more, and 40 pages remained. How many pages
10.   were there in the book?

320.  For,

 12 + 38 = 48 + 38 = 78
 so that 18 remained.  40 pages are one eighth of 8 × 40 = 320.

 18.   a)  3 15 + 4 25 = 7 35 10.   b)  8 29 + 7 39 = 15 59 10.   c)  3 24 + 4 34 = 8 14
 18.   d)  6 58 + 2 78 = 9½ e)  4 56 + 3 56 = 8 23 f)  1 23 + 8 13 = 10

 19.   a)  3 14 + 2 58 = 5 78 b)  2 56 + 7 5 18 = 10 19 c)  7 34 + 1 5 16 = 9 1 16
 11.   d)  6 45 + 9 12 = 16 3 10 e)  4 34 + 1 56 = 6 7 12 f)  3 29 + 2 56 = 6 1 18

13.   Subtract.

 10.    a)  5 34 −2 14 = 3½ b)  4 45 −1 15 = 3 35 c)  3 58 −3 38 = 14

Continue on to the next section.

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