SHORT METHODS. Multiplication and Division. Art. 1. To multiply a number by 50: Multiply of the (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? 2400 + 48 = 2448 (b) Find the sum of the fifteen products. Art. 3. To multiply a number by 52: Take 50 times the number, to which add twice the number. Why? (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? Why? 36 × 331 (d) Find the sum of the nine products. Art. 5. To multiply a number by 331: Multiply of the number by 100. of 36 x 100 = 1200 Art. 6. To multiply a number by 341: the number, to which add the number itself. 331 times 24 = 800 Take 331⁄2 times Why? 800 + 24 = 824 8331+25=8581 24 × 341 25 × 341 (f) Find the sum of the twelve products. Art. 7. To multiply a number by 351: the number, to which add twice the number. Take 331 times Why? = 24 × 351 33 times 24 = 800 800 +48 848 (g) Find the sum of the nine products. Art. 8. To multiply a number by 32: Take 33 times the number, from which subtract the number itself. Why? Art. 9. To multiply a number by 25: Multiply of the (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? Art. 11. To multiply a number by 27: Take 25 times the number, to which add twice the number. Why? Art. 12. To multiply a number by 24: Take 25 times the number, from which subtract the number itself. Why? €768 792 (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? (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 |