How to Complete Three-Digit Subtraction Equations

😃 In previous lessons, you learned how to solve 3-digit subtraction equations. 

Sometimes, you may have to solve equations like these:

482 - ? = 231

? - 314 = 625

How do you find the missing numbers? 🤔

Let's learn that today! 🤗

But first, let's quickly review subtraction.

Subtraction Review ⚡️

      Subtraction is taking away part of a number.

✅ A subtraction equation has 3 parts - the minuend, the subtrahend and the difference.

• Minuend - This is the biggest number, or the whole, from which a part will be taken away.
  
• Subtrahend - This is the part that is taken away from the minuend.
  
• Difference - This is the part that is left-over after subtraction.
  

Completing 3-Digit Subtraction Equations

Now, let's look at our previous examples.

Example 1

482 - ? = 231

Can you tell which is the whole, and which are the parts in this equation?

Very good!

482 - ? = 231
Whole - Part = Part

You have the whole and one part.

How can you find the other part? 🤔

You got it! 🤗

      When one part is missing, subtract the part you know from the whole.

Let's do it! 😎

482 - 231 = ?

Great job! 👏 The missing number is 251.

Example 2

? - 314 = 625

Do we need to find the whole or a part? 🤔

Correct again! 👍

? - 314 = 625
Whole - Part = Part

This time, we have both the parts and the whole is missing.

      When the whole is missing, we add the parts together.

314 + 625 = ?

Great work! 👏 The missing number is 939.

Awesome! 😎

Now, you know how to complete 3-digit subtraction equations! 🤗 

Next, complete the practice to help you understand more.