The Wattbots need an annual check-up to show their strengths and weaknesses. Amber and Sam help by doing tests on each one and writing down the information. They realise that the information they have collected is difficult to understand in its present form. Numberella shows them how to make a table to help to organise the data and make it easier to read. The Wattbots are assessed on energy, strength and skill, so when a large girder traps Uncle Zak the children can use their table to find a Wattbot with high energy and strength to rescue him.