Step 6 Objective

Consolidate and extend mental methods of calculation, working with decimals, fractions and percentages, squares and square roots, cubes and cube roots: solve word problems mentally.


Probing questions

How do you decide whether you can do a calculation mentally? What do you look for?

How would you do this division mentally? e.g. 420 ÷ 15

One eighth is 0.125 as a decimal. What other decimal equivalents can you find from this?

What percentages of quantities can you easily work out in your head?

How would you go about estimating a square root, for example, of 30?