About Subtraction

Subtraction is the process of taking away one number from another. The result is called the difference.

Properties:

• Subtraction is not commutative (a - b ≠ b - a)
• Subtraction is not associative ((a - b) - c ≠ a - (b - c))
• Subtracting zero from a number gives the same number
• Subtracting a number from itself gives zero

Tips:

• Line up numbers by place value
• Borrow when necessary
• Check your answer by adding the difference to the subtrahend
• Use mental math for simple calculations