The first number has to be a number between \(1\) and \(10\)(\(10\) not included). If we insert a decimal point after the digit \(3\), then count how many times we must move that point to get to the end of the number, that provides the power of \(10\) required.

The first number has to be a number between \(1\) and \(10\)(\(10\) not included). If we insert a decimal point after the digit \(5\), then count how many times we must move that point to get to the end of the number, that provides the power of \(10\) required.

Since \(1\) million is \(10^6\), we start by writing the number as \(21.5\times10^{6}\). The first number has to be a number between \(1\) and \(10\)(\(10\) not included), we must divide it by \(10\). To balance out that division so as not to change the number, we must multiply \(10^6\) by \(10\). This gives the answer shown.

Start by writing out the first number, \(1.2\), and since the power is \(3\), move the decimal point to the right \(3\) places. Then fill in the gaps with zeros.

Start by writing out the first number, \(5.5\), and since the power is minus \(4\), move the decimal point to the left \(4\) places. Then fill in the gaps with zeros.

The first number has to be a number between \(1\) and \(10\)(\(10\) not included). If we insert a decimal point after the digit \(6\), then count how many times we must move that point to get to the decimal, that provides the power of \(10\) required.

The number given is \(0.00000000000463\). There are \(11\) zeros between the decimal point and the first significant figure.

Division: \((1.7\times10^{3})\div12=141.667 s\). The answer is shown to the nearest second.

Since \(8\) minutes is \(420\) seconds, multiply \(3\times10^{8}\times420=1.44\times10^{11}\space m\). To change metres into kilometres, we divide by \(1000\). However, dividing by \(10^{3}\) is equivalent to subtracting \(3\) from the power, leaving \(1.44\times10^{8}\space km\).

Since the first number has to be a number between \(1\) and \(10\)(\(10\) not included), we must divide it by \(100\) or \(10^{2}\). To balance out that division so as not to change the number, we must multiply \(10^{-6}\) by \(10^2\). This gives the answer shown.