This set of cards is designed to introduce the concept that the symbol can be drawn as a working process for the calculation of sums. Learners quickly take up the simple system of symbols and draw them as a small circle or large dot for each unit; a long rode or thick line for each ten; a square for each hundred; and a crossed square for each thousand. I do not encourage learners to bother with the colour coding once they are able to use the symbols to support their own calculations. The symbol system can be used as an aid to understanding about the four mathematical processes and as an aid to prove that an answer to a sum is correct or even to help identify where and why a numerical calculation has given a wrong answer.