Super Columns! Adding 2-Digit Numbers Neatly!

Hello Maths Explorers! Today, we’re going to learn a super neat and organized way to add bigger numbers called Column Addition. It’s like giving your numbers their own special parking spots so they line up perfectly! We’ll start with adding two 2-digit numbers, and the best part is, for these first problems, there’s no carrying (or regrouping) needed. Easy peasy!

What is Column Addition? And How Do We Do It?

Column addition helps us add numbers by lining them up based on their place value – ones with ones, and tens with tens. It makes sure we add the right parts of the numbers together.

Let’s Add Two 2-Digit Numbers: Example 34 + 25

Here’s how you set it up and solve it:

Step 1: Write the numbers one above the other. Make sure the ones digits are lined up in one column, and the tens digits are lined up in another column. It’s like they’re standing in straight lines!

   T O  (T for Tens, O for Ones)
   3 4
+  2 5
------  (Draw a line underneath for your answer)

Step 2: Add the Ones Column First. Look at the numbers in the ‘Ones’ (O) column. In our example, it’s 4 and 5. Add them together: 4 + 5 = 9. Write the answer (9) directly below the ones column, under the line.

   T O
   3 4
+  2 5
------
     9

Step 3: Add the Tens Column Next. Now look at the numbers in the ‘Tens’ (T) column. In our example, it’s 3 and 2. Add them together: 3 + 2 = 5. Write the answer (5) directly below the tens column, under the line.

   T O
   3 4
+  2 5
------
  5 9

So, 34 + 25 = 59! You’ve used column addition!

For all the questions on this page, the sum of the ones digits will be 9 or less, so you won’t need to worry about “carrying” any numbers over to the next column.

Practice Your Column Addition Skills! (18 Questions)

Ready to try setting up and solving some column additions yourself? Here are 18 questions where you’ll add two 2-digit numbers. Remember to line up your ones and tens carefully, and add the ones column first!

(Your web app with the 18 questions will go here. The web-app should ideally allow children to see or input numbers in a columnar format.)

Why is Column Addition a Great Method?

• It’s Organized: Lining up the numbers helps prevent mistakes.
• Handles Bigger Numbers: It’s a method you can use for much larger numbers as you learn more.
• Clear Steps: The step-by-step process is easy to follow.
• Builds Place Value Understanding: It reinforces the idea of ones, tens, hundreds, etc.

Tips for Grown-Ups: Guiding Column Addition Beginners

Column addition is a foundational written method. For this introductory stage (two 2-digit numbers, no regrouping/carrying), the focus is on correct digit alignment and understanding the process of adding columns separately.

• Emphasise Place Value Alignment: Use squared paper or draw columns to help children line up the ones and tens digits accurately. Label columns ‘T’ (Tens) and ‘O’ (Ones) at the start.
• Always Start with the Ones: Stress the importance of adding the ones column first. This becomes crucial when regrouping is introduced later.
• Verbalise the Steps: Encourage children to say aloud what they are doing, e.g., “First, I add the ones: 4 plus 5 equals 9. I write 9 in the ones column. Next, I add the tens: 3 plus 2 equals 5. I write 5 in the tens column.”
• Keep it Simple (No Carrying Yet): Ensure all practice examples at this stage have ones digits that sum to 9 or less, so carrying is not required.