What is three-quarters of six hours? Tick the correct box. Is it four hours, 30 minutes, 430 minutes, 450 minutes, or four hours, 50 minutes?
In order to answer this question, we firstly need to calculate three-quarters of six hours. One way of working this out would be to find one-quarter of six hours and multiply it by three. One-half of six is equal to three. To find one-quarter of six, we need to halve this answer. One-half of three or three divided by two is equal to 1.5.
This means that one-quarter of six hours is 1.5 hours. We want three-quarters. So we need to add 1.5, 1.5, and 1.5 or multiply 1.5 by three. Either way, we get an answer of 4.5 hours or four and a half hours.
An alternative method for finding three-quarters of six hours would be to multiply three-quarters by six. Three-quarters multiplied by six can be written as three-quarters multiplied by six over one. We can cancel by dividing by two. This leaves us with three over two multiplied by three over one.
Multiplying the numerators gives us nine and multiplying the denominators gives us two. We are left with nine over two or nine-halves. Nine divided by two is equal to 4.5. So once again, we get an answer of 4.5 hours.
We now need to work out which of our four answers corresponds to 4.5 hours. One hour is equal to 60 minutes. This means that half an hour or 0.5 of an hour is equal to 30 minutes. 4.5 hours is equal to four hours and 30 minutes. This means that the correct option was the first one.
A common mistake here would be to think that 50 minutes was half an hour. But as there is 60 minutes in one hour, a half an hour will only be 30 minutes. So the bottom answer four hours, 50 minutes is incorrect. As there are 60 minutes in one hour, the middle two answers of 430 minutes and 450 minutes would both be over seven hours, so are also incorrect.
The correct answer three-quarters of six hours was four hours and 30 minutes.