Subtraction to 20 colour by code — butterfly

Subtraction across ten is where a lot of children fall back on finger-counting even after addition feels automatic, because take-away does not have the same obvious visual model. This sheet keeps every answer between 3 and 8 specifically so counting back is still a viable check for a child who is not yet confident.

Pairing it with the rocket version gives two genuinely different problem sets on the same narrow skill, which is what spaced practice on subtraction actually needs — repetition of the SKILL, not memorisation of one specific sheet.