Arrange these numbers from smallest to largest.
$2.1\times10^{-3},\;4.2\times10^{-4},\;1.7\times10^{-5},\;3.5\times10^{-4}$.
(b(i))[1]
With $P=6\times10^{10},\;Q=5\times10^{9}$. Find $P-Q$. Give your answer in standard form.
(b(ii))[1]
With $P=6\times10^{10},\;Q=5\times10^{9}$. Find $PQ$. Give your answer in standard form.
Worked solution & mark scheme
This 3-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Ascending order: $1.7\times10^{-5}, 3.5\times10^{-4}, 4.2\times10^{-4}, 2.1\times10^{-3}$” …