A poster displaying subtraction by trading.
Print this poster out in A3 or larger and display it in your classroom.
Refer to it when you are working with subtraction concepts.
Subtraction by trading is used to subtract numbers with more than one digit.
32-12 = 20
1. Rearrange the equation so that the numbers line up above and below.
2. Do the subtractions one column at a time.
What if a column has a smaller number on top?
25-18 = 7
1. Make the 5 larger by trading 1 from the tens column.