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THE NEW STUDENT'S  REFERENCE WORK

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EXEECISE 20.

Find the L. C. M. of

1.   30,  45,  64

2.   36,  45,  60

3.   27,  33,  54

4.   12,  18,  96

5.   20,  27,  45

6.   14,  96,  128

7.   15,  26,  39

8.   25,  60,  180

9.   16,  42,  80 10.    42,  56,  70

11.   22,  44, 88, 108

12.   27,  32, 36, 56

13.   28,  56, 72, 96

14.   14,  42, 63, 108

15.   21,  63, 72, 99

16.   72,  80, 84, 96

17.   42,  48, 84, 126

18.   18,  20, 36, 72

19.   32,  36, 49, 56

20.   28,  72, 84, 96

The least common multiple of large numbers is of little importance, and is confusing to a child at this stage of mathematics.

FRACTIONS.

The first circle represents a unit.

The second circle is divided into two equal parts: each part is called one half (%).

The third circle is divided into three equal parts: each part is called one third (1/3) ; two parts are called two thirds (2/3).

The fourth circle is divided in four equal parts: each part is called one fourth (^4) ; two parts are called two fourths (2/4) ; 2/4 are the same as %; three parts are called three fourths (%).

Continue the work through fifths, sixths, sevenths, eighths, ninths, tenths, and twelfths.

In expressing a fraction, as %, the number below the line is called the denominator; the number above the line is called the numerator.

The denominator tells into how many parts the unit is divided^ or the size of the parts.

The numerator tells how many parts are used.

The numerator and denominator are called the terms of a fraction.

A fraction whose numerator is less than its denominator is called a proper fraction. As %, %, 5/6, 11/12.