To multiply \(23.7\) by \(4\) without using a calculator, you can set it out like this: One decimal place is used in the calculation therefore the solution should also contain one decimal place.

Multiplying and dividing whole numbers by numbers greater than 0 and less than 1 can be broken into a whole number calculation followed by multiplying or dividing by a power of 10, for example 10, 100 ...