Simply present that you would split them up as a factor of two. ( make two lines going either vertically or horizontally. place in varriations, a marble in one line and a marble in the other and then count the leftover
The y- axis goes up and down.
and......
The x- axis goes from left right.
Multiply the values then either divide by 2 or multiply by 2
6r-24+r+30-7r (the we divide the regular numbers on one side and the others on the other side)Like this:
(6r+r-7r)+(-24+30)
(7r-7r)+6
And the final answer is 6
