Which of the following would most likely be the mass of 10 exercise books?
- 8 g
- 80 g
- 800 g
- 8 kg
Need a hint?
Think about the mass of one book first, then about how many books there are.
Worked answer
- One exercise book has a mass of about 80 g.
- Multiply by 10 for 10 books: 80 g × 10 = 800 g.
- 800 g is less than 1 kg, so 800 g is the most likely mass.
Answer: 800 g
The mistake this question tests
Habit
Left out the units
Pupils often pick 80 g because they estimate the mass of only one book and forget to multiply by 10.
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