It is not often that we perform detailed numerical calculations with only pen and paper.

This unit aims to develop skills that are relevant in a cell-phone-generally-within-reach society:

  • Recall of basic number facts;
  • The ability to ball park calculations by rounding to one or two significant figures;
  • The ability to double or halve, repeatedly;
  • The ability to multiply or divide by 5, 20 or 25;
  • The ability to convert miles to km, and km to miles. Highway entertainment?
  • The ability to compute a tax or a tip.

Getting a calculation correct to three significant figures without technology is a party trick or mental entertainment for those that love arithmetic. Knowing that an answer is within a reasonable ball park is required for any person who uses technology to do their arithmetic.

Numeracy Menu

Multiply by 5, 20, 25

Mental Arithmetic Target Practice 1

Estimating (Multiplication)

Negative Number Sequences

Multiply, Divide Powers of Ten