Question 9 of 47intermediate✨ CreateShort Answer3 marks

Give 5 examples of multiplication problems where halving and doubling will help in finding the product easily. Find the products as well.

Correct Answer

Five examples where halving and doubling helps:

Example 1: 25×1625 \times 16 = 400 Half of 16 is 8, double of 25 is 50 So 8×508 \times 50 = 400

Example 2: 5×245 \times 24 = 120 Half of 24 is 12, double of 5 is 10 So 12×1012 \times 10 = 120

Example 3: 50×1450 \times 14 = 700 Half of 50 is 25, double of 14 is 28 So 25×2825 \times 28 = 700

Example 4: 15×1815 \times 18 = 270 Half of 18 is 9, double of 15 is 30 So 9×309 \times 30 = 270

Example 5: 25×2425 \times 24 = 600 Half of 24 is 12, double of 25 is 50 So 12×5012 \times 50 = 600

Exercise: Doubling and Halving | Q: 4 | (Page Page 7)
For More Understanding

Explanation

Students should create their own examples where one factor is 5, 25, or 50, as doubling these creates friendly numbers (10, 50, 100) that are easy to multiply.

Solution Steps

  1. Identify a multiplication problem where one factor can be easily halved.

  2. Double the other factor to maintain the same product.

  3. Multiply the new factors to find the answer.

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