Completing Three-Digit Subtraction Equations

π In previous lessons, you learned how to solve 3-digit subtraction equations and word problems.Β

But, sometimes, we may have to solve equations like these:

482 -?= 231

?- 314 = 625

How do you find the missing numbers? π€

Let's learn that today! π€

But first, let's quickly review subtraction.

**Subtraction **is taking away part of a number.

β
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.

Now, let's look at our previous examples, one-by-one. π€

π Let's take the first example.

482 -?= 231

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

Very good! π

482-?=231Whole-Part=Part

β
**482 is the whole,** and **231 **and **the missing number **are its **parts.**

You have the whole and one part.

Using them, how can you find the other part? π€

You got it! π€

**When one part is missing,** subtract the part we know (subtrahend) from the whole (the minuend).

Let's do it! π

482-231=?

Great job! π The missing number is **251.**

Let's use the answer to complete the equation we began with.

482 -251= 231

Nice job! π

π Now, let's look at the second example.

?- 314 = 625

Do we need to find the whole or its parts in this equation? π€

Correct again! π

?-314=625Whole-Part=Part

β
Here, **the missing number is the whole** and the **314 and 625 are its parts.**

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

How will you find it? π€

That's right!Β

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

314+625=?

Great work! π The missing number is **939.**

Let's use this answer to complete the equation we started with.

939- 314 = 625

Awesome! π

π€ Now you know how to complete 3-digit subtraction equations!Β

Start your practice below.

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