UK K12 GCSE/A-Level: Year 3 KS2 Mathematics - Addition and Subtraction, 3-Digit Numbers Columnar

Learning Objectives

By the end of this topic, students will be able to: - Add and subtract 3-digit numbers using columnar methods - Understand the concept of place value and its application in columnar addition and subtraction - Apply columnar methods to solve multi-digit addition and subtraction problems - Recognize and correct common errors in columnar addition and subtraction

Core Concepts

Columnar addition and subtraction involve breaking down multi-digit numbers into their place value components and performing operations on these components. This is achieved by lining up the numbers vertically, with each place value (ones, tens, hundreds) aligned correctly.

For example, consider the addition of 247 and 153:

  247
+ 153
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To add these numbers, we break them down into their place value components:

• Hundreds: 2 + 1 = 3
• Tens: 4 + 5 = 9
• Ones: 7 + 3 = 10

We then combine these components to form the final answer:

  3
  9
 10
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This results in a final answer of 400.