I am remaking the ITPs so that they will work on all modern browsers and tablets. They will remain freely available to all without the need for a subscription. This ITP allows you to compare two rows of beads and to analyse the calculations they can represent. It can be used to promote the language of addition and subtraction, particularly the interpretation of difference. The ITP operates as a series of animations which show how the rows of beads can be represented by two number lines and then as a single number line with the difference indicated by a ‘jump’.