Page 79 - Math Genius C3

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\ 01-Oct-2025 Bharat Arora Proof-10 Reader’s Sign _______________________ Date __________

Step 4: Add the numbers diagonally to find the answer. 1 5 1 6
While adding the numbers diagonally, if the sum 5 8 3

is of two digits, retain the ones and carry over the 1 2 0 2 4 4
tens to the next diagonal and add with them. 2 + 5 + 1 + 1 = 9 0 4

Thus, 56 × 34 = 1904. 0 + 2 + 8 = 1

practice time 4D

1. Multiply the following:
(a) H t O (b) th H t O (c) th H t O (d) th H t O
2 1 4 2 2 3 7 3
× 3 4 × 4 2 × 5 6 × 6 4

+ + + +

(e) th H t O (f) th H t O (g) th H t O (h) th H t O
2 0 4 3 4 3 2 1 6 2 7 3
× 1 2 × 2 2 × 4 3 × 2 7

+ + + +

2. Write in columns and find the product.
(a) 14 × 22 (b) 31 × 16 (c) 174 × 42 (d) 365 × 22

3. Multiply the following using the lattice multiplication.
(a) 21 × 11 = _____ (b) 24 × 14 = _____ (c) 33 × 14 = _____

exploring Multiplication

Multiplying by expanding the bigger number

Example: Multiply: (a) 67 × 5 (b) 143 × 3
Solution: (a) Step 1: Write 67 as 60 + 7. (b) Step 1: Write 143 as 100 + 40 + 3.
Step 2: Multiply each term of the Step 2: Multiply each term of the

expanded form by 5 and expanded form by 3 and
add the products. add the products.
60 × 5 = 300 100 × 3 = 300

7 × 5 = + 35 40 × 3 = 120
335 3 × 3 = + 9

Thus, 67 × 5 = 335. 429
Thus, 143 × 3 = 429.

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