Loop game - addition and subtraction

This is really useful as an engaging starter. When played as a loop game this is a whole class activity. Each student has one or two cards, each question leads to an answer on someone else's card. This means the students work out the answer to every question in their head as the game goes along. Even more motivation can be provided by timing how long the class takes to complete the loop, then swapping the cards around and trying to beat their time. If you print this page onto card it can be used many times.
Alternatively, each student or pair could be given a copy and asked to cut out the cards then stick them in order in their book.
The questions are on addition and subtraction, suitable for KS2 or KS3.
There are 36 cards.