Addition to 20 colour by code — butterfly

The problems are generated fresh each time the PDF is built, so this is not the same six sums as the rocket sheet with a different picture stapled on — running both across a week gives real additional repetition on the same narrow skill rather than a rehash.

Six answers (11 through 16) map to six legend colours exactly as they do on every sheet in this set, which keeps the rule simple enough that a five- or six-year-old can hold it in mind without re-reading instructions.