Negative number game (boxes) starter/plenary

This is a two player game. Based on the old game of ‘boxes’ where you have to get the most number of squares on a dotty grid by joining up two dots and take it in turns until all boxes have been filled. In this version you have to add up the score as you go along and each box has an integer in it from 5 to -5 and students have to add their scores together as they go along. This is to get students to add small positive and negative numbers.