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(ii) To multiply a number by 200, 300, 400, .... multiply it by 2, 3, 4, .... and put

two zeros after the product.

For example: 15 × 500 = 7500

Example: Multiply 145 by : 2 3
60

Solution: First multiply 145 by 6 → 867 1 4 5

Put one zero after 870 → 8700 × 6

so 145 × 60 = 8700 8 7 0

MENTAL MATHS-2

A. Multiply orally:

(a) 0 30 × 00 60 = ______ (b) 0 50 × 00 80 = ______

(c) 00 6 × 1000 = ______ (d) 587 × 00 10 × ______

(e) 430 × 00 10 = ______ (f) 0 12 × 0 800 = ______

(g) 100 × 00 10 = ______ (h) 0 18 × 0 100 = ______

(i) 0 70 × 0 100 = ______ (j) 0 10 × 00 10 = ______

(k) 0 60 × 00 10 = ______ (l) 0 70 × 00 20 = ______

(m) 0 80 × 00 40 = ______ (n) 0 50 × 00 30 = ______

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Multiplication
Mathematics-3