Basic Mathematics

# Mental Shortcuts - Basic Warmup

Which of the following is equivalent to calculating 20% of 36?

Instead of multiplying by 5, it might be easier to multiply by 10.

Which of these is an easier version of $72 \times 5$?

Which of these gives a nice shortcut to compute $34 \times 11$ in your head?

Which of these is equivalent to $8888 \times 5 ?$

When calculating $100-36$ by hand, we have to do a lot of "borrowing". It would be much easier to subtract from 99 instead. Which of the following is equivalent to $100-36$?

×