Just for fun
We've looked at some typical examples of calculations relating to underlayment and primer volumes in the lesson:Estimating quantities. You'll have noticed that the workings for these exercises are set out in the standard mathematical format that you used at school.
However, when you're out on-site there are often times where you can take a shortcut and do the calculations in your head.
Below are two examples of these sorts of calculations. The first one involves finding a simple factor that can be applied to the problem. The second one is basically a rounding-off exercise to simplify the numbers.
See how you go solving these problems in your head. Click in the answer box for each one to select your answer.
For more practice on rounding off numbers, go to the unit: Making measurements.
| Diagram | Question | Answer |
|---|---|---|
 | If a 20kg bag of levelling compound will cover 4 m2 at 3 mm thick, how many bags are required to cover 8 m2 at 6 mm thick? | 4 |
 | You have to prime the floor area shown at left. You've got an unopened 5 litre container of primer, which will cover 30 m2. Will this be enough to cover the floor? | yes |