Progress in Mathematics Chapter 7
Table of Contents
- 7.1: Addition Properties Fractions
- 7.1.1 Addition Properties of Fractions
- 7.2: Estimate Sums and Differences
- 7.3: Add Fractions
- 7.3.1Adding Fractions
- 7.4: Add Mixed Numbers
- 7.5: Subtract Fractions
- 7.6: Subtract Mixed Numbers
- 7.7: Mental Math - Addition and Subtraction
- 7.8: Addition and Subtraction Expressions with Fractions
- 7.9: Addition and Subtraction Equations with Fractions
- 7.10: Working Backwards
7.1.1 Addition Properties of Fractions
Commutative Property
Just like in normal addition, the order of adding 2 fractions can be switched around as well.
Try writing two fractions and then adding them in the model provided below. [br][br]Next, switch the order and add them again. See what happens!
Instructions for Model
To use this model, enter in values for fractions. To get new values, press new fractions.
7.3.1Adding Fractions
Finding the LCD
In order to add two fractions, we must first make sure we can find the LCD of the two fractions first.[br][br]The LCD is the Least Common Denominator of the 2 fractions. We can find it by finding the least common multiple of the denominators.[br][br]So we keep adding the denominators onto themselves until we find the least common one.
Exercise
Use the model below to visualize adding fractions using the least common denominator.
Instructions for Model
Move the sliders to manipulate the numerators and denominators of both fractions.[br][br]We can go up to 10/10 on both sides. [br][br]Match the given numbers, then slide one diagram onto the other to get the LCD.