Estimate and Use Inverse to Check - KS2

These differentiated resources are ideal for lower KS2 children when you are teaching how to apply knowledge of rounding and using the inverse to check calculations. For each question, the numbers involved are represented pictorially and the line between green and yellow backgrounds helps pupils to see if they need to round up or down. Each question has these steps:

1. Round the two numbers to the nearest 10
2. Add/subtract these rounded numbers in the space below (‘estimate’)
3. Do the calculation using the actual numbers and see if the estimate was close
4. Put the three numbers in the calculation into the ‘Singapore bar’ template in the third cell (largest number in the top cell).
5. Do an inverse calculation to check

For the ‘2 Chillies’ resource, there is no scaffolding for the children’s calculations.