Lesson 1.5: Add and Subtract Rational Numbers

Lesson 1.5
Add and Subtract Rational Numbers

Definition:

Rational Number: A rational number is any number that can be written as a fraction of two integers where the denominator is non-zero.
Examples: Any fraction, any integer, any repeating or terminating decimals.

Today's Goal:

In this lesson, we will take what we learned from adding and subtracting integers and apply that to rational numbers as well.
Note: The rules are the exact same.

Multiple Choice

Solve:

$$2\ \frac{3}{4}-4\ \frac{1}{4}$$

• $$-2\ \frac{1}{4}$$

• $$2\ \frac{1}{4}$$

• $$-1\ \frac{1}{2}$$

• $$1\ \frac{1}{2}$$

Multiple Choice

$$-5\ \frac{1}{4}-\left(-6\ \frac{1}{2}\right)$$

• $$-1\ \frac{1}{4}$$

• $$1\ \frac{1}{4}$$

• $$-11\ \frac{3}{4}$$

• $$11\ \frac{3}{4}$$

​Solve: -2.5 - (6.8)

Multiple Choice

Solve: 14.8 - (-32.4)

• 17.6

• -17.6

• 47.2

• -47.2

Multiple Choice

25.27 - 35.42

• 60.69

• -60.69

• 10.15

• -10.15

​Example: The temp in a town is 36.6 degrees during the day and (-12.6) degrees at night. What is the temp change from day to night?

Multiple Choice

The temp at RMS is 102 degrees during the day and -14 degrees at night (not really). What is the difference in the temp from day to night?

• 88 degrees

• -88 degrees

• 116 degrees

• -116 degrees

​Conclusion: Two complete sentences about what you learned.

​I learned when adding or subtracting rational numbers the rules are ______ as adding or subtracting integers.

To add or subtract fractions I must make sure the _____ is the same.

When adding or subtracting decimals, I make sure to _____ the decimal places.