7.5 Standard form — Practise

1. Write $6\,320\,000$ in standard form.
2. Write $0.000091$ in standard form.
3. Work out $(2\times10^5)(3\times10^4)$ in standard form.
4. Work out $(8\times10^7)\\div(2\times10^3)$ in standard form.
5. Work out $4.5\times10^6+2.3\times10^6$.
6. Work out $5.2\times10^4-3\times10^3$.
7. Which is greater: $7.4\times10^{-3}$ or $6.9\times10^{-2}$?
8. A bacterium is $0.000004$ m long. Write this length in standard form.
9. H H Work out $(6\times10^{-4})(5\times10^8)\\div(3\times10^2)$ in standard form.
10. Which method applies to add $8.2\times10^5$ and $3.7\times10^4$? Then calculate.