Missing Operations

Lesson Plan - Get It!

Audio:

It is possible to solve math equations that are missing information. That's algebra!

You just need to know a couple of tricks to help you do it.

Finding the missing operation (=, -, x or ÷) is like solving a puzzle. Take a look at the very colorful equation below. Let's break this down.

(4 + 4) ?7 = 1

First, we need to add the numbers in the parentheses. We know 4 + 4 = 8!

• Is that what you said?

Awesome! Here's our new equation:

8 ? 7 = 1

• Now, what operator, if placed between the numbers 8 and 7, will result in the number "1"?

It's definitely not addition or the plus sign (+) because 8 + 7 = 15.

It's definitely not multiplication (x) because 8 x 7 = 56!

It's also definitely not division, because 8 ÷ 7 would be equal to a number that is less than 1.

So, we found our answer! Our missing operator is the minus sign (-) and our missing operation is subtraction!

8 - 7 = 1

Way to go!

Next, complete the Determine the Missing Operation in an Equation activity from Scholastic Study to learn how to solve equations where the operational symbol is missing.

1. Click on the green STEP BY STEP circle to begin.
2. Use the SHOW ME and NEXT buttons to navigate through the steps.
3. Then, click on the WATCH OUT! tab.
4. Keep the Scholastic Study Jams page open in a separate window to use again later in the lesson.

Finally, for some more practice, watch Filling in missing operations to make an equation, from Betsy Fochs:

Great job learning! Head on over to the Got It? section and test your skills.