Question 15 of 33intermediate🔧 ApplyNumerical3 marks

Try to subtract: −3 − (+5). How many zero pairs will you have to put in? What is the result?

Correct Answer

Step 1: Start with 3 negative tokens (representing −3).

Step 2: Need to remove 5 positive tokens (to subtract +5).

Step 3: No positive tokens available, so add 5 zero pairs.

Step 4: Each zero pair = 1 positive + 1 negative token.

Step 5: Now have 3 + 5 = 8 negative tokens and 5 positive tokens.

Step 6: Remove 5 positive tokens.

Step 7: 8 negative tokens remain.

Answer: −3 − (+5) = −8. Zero pairs needed: 5.

Exercise: Figure it Out (Section 10) | Q: 1 | (Page Page 18)
For More Understanding

Explanation

The chapter explains the token method for subtraction when we need to remove tokens that aren't available. We add zero pairs (one positive and one negative token) which don't change the value. Then we can remove the required tokens. In this case, we need to remove 5 positive tokens, so we add 5 zero pairs.

Solution Steps

  1. Step 1: Start with 3 negative tokens (representing −3)

  2. Step 2: Need to remove 5 positive tokens (to subtract +5)

  3. Step 3: No positive tokens available, so add 5 zero pairs

  4. Step 4: Each zero pair = 1 positive + 1 negative token

  5. Step 5: Now have 3 + 5 = 8 negative tokens and 5 positive tokens

  6. Step 6: Remove 5 positive tokens

  7. Step 7: 8 negative tokens remain

  8. Step 8: Result = −8

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