Colour by substitution 2 with extension

As the title suggests, this is a colouring sheet for practising solving questions where substitution is involved. It covers adding, subtracting, multiplying, powers, roots and order of operations including negative numbers. Unlike other maths colouring sheets, each sheet only requires four different colours and therefore requires fewer teacher supplies. Students solve the answers to the questions and colour based on their solution. This then creates a pattern which looks great on a classroom wall. Two solutions do not fit the pattern and students are encouraged to find their own questions that will fit the pattern allowing for stretch and challenge. The solution is the pattern displayed. The white spaces are where students are required to find solutions that do fit the pattern.
All feedback gratefully accepted.