Year 3: Adding 2-Digit Numbers (With Regrouping)
Add the ones. If the total is 10 or more, write the ones digit in the answer. Write the carried ten in the small box below the tens answer. Then, add all the tens, including the one you carried!
Write your answers and any carried tens in the boxes.
Hello Maths Superstars! You've done a brilliant job learning to add 2-digit numbers in columns when there's no carrying. Now, get ready for the next exciting step: learning how to carry (or regroup) when the numbers in your ones column add up to 10 or more! It's like giving an extra ten a special trip to the tens column.
When we add the ones column and the answer is 10 or more (like 12, 15, or 18), we can't write two digits in the ones place of our main answer line. So, we "carry" the ten part of that number over to the tens column to be added in with the other tens. It's all about understanding that 10 ones make 1 ten!
Let's Add with Carrying: Example 37 + 25
Here’s how we do it:
Step 1: Set up your column addition. Write the numbers one above the other, lining up the tens and ones.
T O (T for Tens, O for Ones)
3 7
+ 2 5
------ (Draw a line for your answer)
Step 2: Add the Ones Column First. Look at the 'Ones' (O) column: 7 + 5. 7 + 5 = 12. Now, 12 has 1 ten and 2 ones. We write the 2 ones under the ones column. We "carry" the 1 ten over to the top of the tens column (some people write it small just above the first number in the tens column, or just below the tens column line to be added in next).
(¹ ) <-- This is the carried 1 ten
T O
3 7
+ 2 5
------
2
Step 3: Add the Tens Column (including the carried ten!). Now look at the 'Tens' (T) column. We have 3 tens and 2 tens, PLUS the 1 ten we carried over. So, we add: 1 (carried ten) + 3 + 2 = 6 tens. Write the answer (6) directly below the tens column.
(¹ )
T O
3 7
+ 2 5
------
6 2
So, 37 + 25 = 62! You've successfully used carrying!
Ready to become a carrying champion? Here are 18 column addition questions where you'll need to add two 2-digit numbers and carry from the ones to the tens. Remember the steps: add the ones, carry if you need to, then add the tens (including your carry!).
(Your web app with the 18 questions will go here. The app should ideally visually support the carrying process or allow space for it.)
"Carrying" (or regrouping) is a pivotal concept in understanding column addition. It's based on the principle that our number system is base-10. When the sum in a column reaches 10 or more, that group of 10 is "carried" as one unit to the next column to the left.