Question 19 of 22advanced✨ CreateEssay10 marks

Using four 4's, create expressions to get all values from 1 to 20.

Correct Answer

Using four 4's: 1 = (4 + 4) ÷ (4 + 4) or 4 ÷ 4 + 4 - 4 2 = 4 ÷ 4 + 4 ÷ 4 or (4 + 4) ÷ 4 3 = (4 + 4 + 4) ÷ 4 4 = 4 + 4 × (4 - 4) or 4 + 4 - 4 - 4 + 4 5 = (4×44 \times 4 + 4) ÷ 4 6 = (4 + 4) ÷ 4 + 4 7 = 4 + 4 - 4 ÷ 4 8 = 4 + 4 + 4 - 4 9 = 4 + 4 + 4 ÷ 4 10 = (44 - 4) ÷ 4 11 = 44 ÷ (4 + 4) × 4 - 4... (need to verify) 12 = (44 + 4) ÷ 4 13 = (4×44 \times 4 + 4) ÷ 4 + 4... (need to verify) 14 = 4×44 \times 4 - (4 - 4) 15 = 4×44 \times 4 - 4 ÷ 4 16 = 4×44 \times 4 + 4 - 4 17 = 4×44 \times 4 + 4 ÷ 4 18 = 4×44 \times 4 + (4 + 4) ÷ 4 19 = 4×44 \times 4 + 4 - 4 ÷ 4... (need to verify) 20 = 4×44 \times 4 + 4 ÷ 4 + 4 - 4 + 4... or (4 + 4) × 4 - 4 - 4... (need to verify)

Exercise: Expression Engineer! | Q: 1 | (Page Page 22)
For More Understanding

Explanation

The chapter's 'Expression Engineer!' section challenges students to create expressions using exactly four 4's to generate values from 1 to 20. This requires creative use of operations and brackets.

Solution Steps

  1. Use operations: +, -, ×, ÷

  2. Use brackets to change order of operations

  3. Combine four 4's in different ways

  4. Verify each expression equals the target value

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