We are looking at working out addition, subtraction, multiplication and division sums using estimating. Estimating uses rounding either to the nearest ten, hundred or thousand in order to work out a sum An example of an addition estimating to the nearest ten is:
67 + 32 =
67 to the nearest ten is 70
32 to the nearest ten is 30
70 + 30 = 100
We have discussed the different ways to show your working out depending on the operation needed, such as the columnar method for addition and the grid method for multiplication.
Which of the below methods are best for you? When the answer is reached using a method it should also be checked using the inverse operation.