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For example, in the expression \(2b^2c\), where \(b = 4\) and \(c = 3\), use the values of \(b\) and \(c\) to calculate the numerical value of the expression:

\(2b^2c = 2 \times b^2 \times c\)

Remember that the rules of BIDMAS/BODMAS show that the order of operations (the order sums should always be completed in) is: Brackets, Indices or Powers, Divide/Multiply and Add/Subtract. This means that the value of \(b^2\) should be calculated before multiplying by 2 or \(c\), as indices come before multiplication.

This gives: \(2b^2c = 2 \times b^2 \times c = 2 \times 4^2 \times 3\) (substituting \(b = 4\) and \(c = 3\)) = \(2 \times 16 \times 3 = 96\)

A common formula is used to convert Fahrenheit (F) to Celsius (C): \(F = \frac{9C}{5} + 32\)

Substitute the value of \(C\) into the equation \(F = \frac{9C}{5} + 32\) to work out the temperature in Fahrenheit.

\(F = \frac{9C}{5} + 32 = \frac{9 \times 20}{5} + 32 = \frac{180}{5} + 32 = 36 + 32 = 68^\circ \text{F}\)