not your grandmother's math
Max has 2 donuts and — You have 0 donuts. You take 1 of Max’s donuts. How many donuts do Max and you each have? Max has 1 donut and you have 1 donut: WRONG! Max has 2 donuts and you have 1 black eye: CORRECT!
Max has 2 donuts and — You have 0 donuts. You take 1 of Max’s donuts. How many donuts do Max and you each have? Max has 1 donut and you have 1 donut: WRONG! Max has 2 donuts and you have 1 black eye: CORRECT!