Multiplying Like a Pro: Short Multiplication with Carrying! (2-digit x 1-digit)

Hello Multiplication Experts! You know your times tables and you’re ready for a super neat way to multiply a 2-digit number by a 1-digit number. This is called Short Multiplication, and it’s a formal written method that helps keep your calculations organised. Today, we’re going to learn the important step of carrying when our multiplied numbers get a bit too big for one column!

What is Short Multiplication and How Does “Carrying” Work?

Short multiplication is a way to set out your multiplication problem in columns, similar to column addition. “Carrying” in multiplication happens when you multiply the ones digits and the answer is 10 or more. The “tens” part of that answer gets carried over to be added to the result of the next multiplication step.

Let’s Multiply with Carrying: Example 27 × 3

Here’s the step-by-step guide:

Step 1: Set up your multiplication problem. Write the 2-digit number on top and the 1-digit number below it, usually under the ones digit of the top number. Put the multiplication sign (×) to the left.

   T O  (T for Tens, O for Ones)
   2 7
×    3
------  (Draw a line underneath for your answer)

Step 2: Multiply the Ones Digit. Multiply the ones digit of the top number (7) by the 1-digit number (3). 7 × 3 = 21. Now, 21 has 2 tens and 1 one. Write the 1 one in the ones column of your answer. “Carry” the 2 tens over to the tens column. You can write it small underneath the answer line in the tens column.

   T O
   2 7
×    3
------
     1
  (₂ )  <-- Small 2 carried to the tens column

Step 3: Multiply the Tens Digit and Add the Carry. Now, multiply the tens digit of the top number (2) by the 1-digit number (3). 2 × 3 = 6 (This means 6 tens, or 60). Important: Now, add the 2 tens you carried from the previous step to this result. 6 tens + 2 carried tens = 8 tens. Write this 8 in the tens column of your answer.

   T O
   2 7
×    3
------
  8 1
 (₂ )

So, 27 × 3 = 81! You’ve successfully used short multiplication with carrying!

Another Quick Example: 45 x 4

• Set up: T O 4 5 × 4 -----
• Ones: 5 × 4 = 20. Write down 0, carry the 2 (tens). T O 4 5 × 4 ----- 0 (₂ )
• Tens: 4 × 4 = 16 (tens). Add the carried 2 (tens): 16 + 2 = 18 (tens). Since this is the last step, write down 18. The 8 goes in the tens column, and the 1 goes in the hundreds column. H T O 4 5 × 4 ----- 1 8 0 (₂ )
• So, 45 × 4 = 180.

Practice Your Short Multiplication with Carrying! (18 Questions)

Ready to become a short multiplication champion? Here are 18 questions where you’ll multiply a 2-digit number by a 1-digit number, and you’ll need to use carrying. Set them out neatly, multiply the ones, carry, then multiply the tens and add your carry!

(Your web app with the 18 questions will go here. The app should ideally visually support the carrying process.)

Why is Mastering Short Multiplication with Carrying So Useful?

• It’s an Efficient Written Method: It’s a standard way to multiply that works for bigger numbers too.
• Builds on Times Table Knowledge: You get to use all those multiplication facts you’ve learned!
• Develops Place Value Understanding: Carrying helps you see how tens are made from ones, and hundreds from tens.
• Key for Future Maths: This method is essential for long multiplication and many other topics.

Tips for Grown-Ups: Guiding Short Multiplication with Carrying

Short multiplication with carrying is a significant step in formal written calculation. It requires children to be secure in their multiplication facts and understand place value.

• Ensure Multiplication Facts are Fluent: Children will struggle with the method if they are still counting on their fingers for basic facts like 7×3.
• Clear Notation for Carrying: Teach a consistent place to write the carried digit (often small, below the answer line in the next column, or above the top number’s digit in the next column). Ensure they remember to add this carried digit after performing the next multiplication.
• Verbalise the Steps: Encourage children to say each step aloud: “First, I multiply the ones: 7 times 3 is 21. I write down the 1 and carry the 2 tens. Next, I multiply the tens: 2 times 3 is 6 tens. I add the 2 carried tens, which makes 8 tens. So the answer is 81.”
• Use Place Value Language: Talk about “7 ones times 3” and “2 tens times 3” to reinforce understanding.
• Squared Paper: This helps keep columns aligned, which is vital.