7.3 Rounding and error intervals — Practise

1. Round $38.476$ to 2 decimal places.
2. Round $0.006384$ to 2 significant figures.
3. A length is $12.6$ cm to the nearest $0.1$ cm. Write its error interval.
4. A mass is $540$ g to the nearest $10$ g. Give its lower and upper bounds.
5. Round $7.995$ to 2 decimal places.
6. Estimate $49.8\times19.7$ by rounding each value to 1 significant figure.
7. Round $0.0847$ kg to 2 significant figures.
8. A number rounds to $250$ to the nearest $10$. Is $255$ included in its interval?
9. H H A value is $3.40$ to 3 significant figures. Give its error interval.
10. A time rounds to $6.2$ seconds to the nearest $0.1$ second. Give its interval and explain the upper sign.