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SHORT METHODS.

Multiplication and Division.

Art. 1. To multiply a number by 50: Multiply £ of the number by 100. Why?

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(a) Find the sum of the fifteen products.

Art. 2. To multiply a number by 51: Take 50 times the number, to which add the number itself. Why?

48 x 50 50 times 48 = 2400 2400 + 48 = 2448 37x51 50 times 37 = 1850 1850 + 37 = 1887

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Art. 3. To multiply a number by 52: Take 50 tivies the number, to which add twice the number. Why?

34x52 50 times 34 = 1700 1700 + 68 = 1768 45 x 52 50 times 45 = 2250 2250 + 90 = 2340

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(c) Find the sum of the twelve products.

Art. 4. To multiply a number by 49: Take 50 times the number, from, which subtract the number itself. Why? 24 x 49 50 times 24 = 1200 1200 - 24 = 1176 33 x 49 50»times 33 = 1650 1650 - 33 = 1617

Multiply:
18 by 49 22 by 49 27 by 49
28 by 49 34 by 49 35 by 49
16 by 49 46 by 49 43 by 49

(d) Find the sum of the nine products.

Art. 5. To multiply a number by 33$: Multiply \- of the number by 100. Why?

36 x 33^ | of 36 x 100 = 1200

37 x 33$ I of 37 x 100 = 1233J

Multiply:
24 by 33£ 27 by 33| 28 by 33^
18 by 33^ 21 by 33^ 22 by 33^
30 by 33$ 33 by 33$ 35 by 33^

(e) Find the sum of the nine products.

Art. 6. To multiply a number by 34$: Take 33$ times the number, to which add the number itself. Why?

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Art. 9. To multiply a number by 25: Multiply \ of the number by 100. Why?

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(i) Find the sum of the twelve products.

Art. 10. To multiply a number by 26: Take 25 times the number, to which add the number itself. Why?

36 x 26 25 times 36 = 900 900 + 36 = 936

37 x 26 25 times 37 = 925 925 + 37 = 963

Multiply:

36 by 26 48 by 26 45 by 26

28 by 26 24 by 26 25 by 26

44 by 26 32 by 26 35 by 26

(j) Find the sum of the nine products.

Art. 11. To multiply a number by 27: Take 25 times the number, to which add twice the number. Why?

36 x 27 25 times 36 = 900 900 + 72 = 972

37 x 27 25 times 37 = 925 925 + 74 = 999

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Art. 12. To multiply a number by 24: Take 25 times the number, from ivhich subtract the number itself. Why?

32 x 24 25 times 32 = 800 800 - 32 = 768

33 x 24 25 times 33 = 825 825 - 33 = 792

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(1) Find the sum of the twelve products.

Art. 13. To multiply a number by 20: Multiply £ of the number by 100. How may a number be multiplied by 21? By 22? By 19?

35 x 21 - 20 times 35 = 700 700 + 35 = 735

Multiply:

45 by 21 45 by 22 45 by 19

35 by 21 35 by 22 35 by 19

36 by 21 36 by 22 36 by 19 (m) Find the sum of the nine products.

Art. 14. To multiply a number by 16|: Multiply -\ of the number by 100. How may a number be multiplied by

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