I made the following problem to be used with my year 9. The boxed value was an error and they had to correct it. It also gave students a chance to discuss misconceptions.
I tried to include one where students used the Scale factor for length as 2 and the SF for area as 2
One where students correctly worked out SF for volume but then the length was halved not doubled,
Another question I included had the SF for area being used on a volume
then a question with SF for volume being used instead of area.
I then started to consider some more challenging questions that combined several ideas involving similar shapes, Scales factors and proportion.