AI Tutor
Imagine checking your bank account: you are overdrawn by -\12.50,depositacheckfor, deposit a check for $25\frac{3}{4},andthenamusicsubscriptionchargesyou, and then a music subscription charges you $8.99$.
To find your final balance, you need to combine positive and negative numbers that are trapped in two different formats: decimals and fractions.

Pick One Format

A rational number is any number you can write as a fraction of two integers, ab\frac{a}{b} (where b≠0b \neq 0), which includes all integers, terminating decimals, and repeating decimals.
Before you add or subtract, convert all the terms into the same format: all decimals or all fractions.
How do we handle subtraction without getting confused by multiple minus signs?

Subtraction as Adding the Opposite

Subtracting a number is identical to adding its opposite (the value with the reversed sign), meaning aβˆ’b=a+(βˆ’b)a - b = a + (-b) and aβˆ’(βˆ’b)=a+ba - (-b) = a + b.
Because taking away a debt makes you richer, subtracting a negative always moves you to the right on a number line.
What does this look like when we solve an expression with three different terms?

Worked Example: Decimals and Fractions