Menu

Left to Right

Part of the Numbers & Operations section of Coddy's Pre-Algebra journey. Lesson 2 of 57.

A classic slip: working out $15-6+3$ as 6. That adds $6+3$ first and then takes 9 away. But only the 6 is taken away. The 3 is added.

Plus and minus are equal, so neither one goes first. Work from left to right. $15-6$ is 9. Then $9+3$ is 12.

Challenge

Work out $50-18+2$ .

Try it yourself

50-18+2

Simplify

All lessons in Numbers & Operations

1Order of Operations

Your First AnswerLeft to RightParentheses First Brackets Inside Brackets The Fraction Bar Groups Recap: Order of Operations

4Adding Integers

Adding Two Negatives Different Signs Zero Pairs Adding Several Integers Recap: Adding Integers

7Exponents

Repeated Multiplication Squares and Cubes Powers of Ten Negative Bases Where the Minus Sits Recap: Exponents

10Numbers in Stories

Temperature Changes Money Owed Up and Down Equal Shares Recap: Number Stories

2Mental Math

Friendly Pairs Take Away the Total Recap: Mental Math

5Subtracting Integers

Add the Opposite Subtracting a Negative Plus and Minus in a Row Distance Between Numbers Recap: Subtracting Integers

8Square Roots

Perfect Squares Undoing a Square Roots in Expressions The Root Sign Groups Between Two Whole Numbers Recap: Square Roots

11Final Challenges

Final: Every Rule at Once Final: Roots and Powers Final: The Freezer Final: Over the Bar Final: On the Line

3Negative Numbers

Below Zero Opposites Greater or Less Absolute Value Recap: The Number Line

6Multiplying and Dividing

Negative Times Positive Two Negatives Counting the Negatives Dividing Integers Zero in Division Recap: Multiply and Divide

9Putting It All Together

Powers Before Products Negatives Inside Negative Bases in Sums Everything at Once Recap: The Full Order