Numbers, units and arithmetic
This free course, Numbers, units and arithmetic, will help you to revise whole numbers, decimals and fractions, both positive and negative. You should know when and how to add, subtract, multiply and divide. Although you may have a calculator, you still need to do simple calculations in your head or on paper. Such calculations could be to estimate the size of an answer, as a check for your calculator work.
This OpenLearn course provides a sample of level 1 study in.