YOU ARE LEARNING:
When numbers get more complicated, estimation is useful for getting an approximate answer. It involves rounding numbers to make them easier to calculate with.
Estimation is when you try and make an approximate calculation. It is actually a really useful skill to have a rough idea of how much something is.
It involves using rounded numbers which make the calculation simpler.
For example, if 12 people each go to a restaurant and spend £28, how much will it cost them all together (approximately)?
Round the numbers in the calculation
To find the exact answer, the calculation would be 12×£28. But this is difficult to do quickly in your head. To help, we can round 12 and 28 to easier numbers.
What is 12 rounded to the nearest 10?
What is 28 rounded to the nearest 10?
Now we can multiply 10×30
This is a much easier calculation.
What is 10×30?
£300 is a good estimate.
Estimate the value of 67×11
Estimate the value of 38×23