How to use column subtraction | Year 3 Mathematics PDF Download

What is column subtraction?

• Understanding Column Subtraction: Column subtraction is a method used to subtract numbers that are too large or difficult to subtract mentally. It involves organizing numbers into columns based on their place value.
• Organizing Numbers: When using column subtraction, numbers are separated into ones, tens, hundreds, and thousands columns. It is essential to list the numbers in a column, starting with the ones column first.
• Estimating and Checking: Before performing the actual subtraction, it is a good practice to estimate a rough answer. After subtraction, always check your answer. Remember that subtraction is the opposite of addition, so you can verify your subtraction by adding the result back to the number you subtracted.
  • Estimate first and check afterwards: By estimating, you get a rough idea of the answer before doing the actual subtraction. Always verify your actual answer for accuracy.
  • Subtraction Check with Addition: Subtraction results can always be confirmed by adding the result back to the number subtracted. For example, for 182 - 37 = 145, you can check by adding 145 + 37 = 182.
  • Key Words Indicating Subtraction: Several words indicate subtraction in a problem. These include 'take away,' 'difference,' 'less than,' 'minus,' 'decrease,' 'fewer than,' and 'reduce.' When you encounter these words, you know that the operation involves subtraction.