AI Tutor
If you owe a friend \3andtheydecidetocancelthatdebt,yourtotalbalanceactuallygoesupbyand they decide to cancel that debt, your total balance actually goes up by$3$.
Taking away a negative amount makes you richer, not poorer. Let's look at why this works using visual models.

Counters and Zero Pairs

A zero pair is a positive value paired with an equal negative value, which cancels out to total zero, like (+0.5)+(βˆ’0.5)=0(+0.5) + (-0.5) = 0.
Because zero pairs equal zero, you can add as many of them as you need to a group without changing its value.
To solve 1.0βˆ’(βˆ’0.5)1.0 - (-0.5), we needed to remove a βˆ’0.5-0.5 counter that wasn't there yet.
Adding a zero pair allowed us to pull out the negative value, leaving three positive halves: +1.5+1.5.
Counters work great for discrete pieces, but how do we visualize continuous decimals and fractions?

The Number Line Model

On a number line, subtraction tells you to turn around and move in the opposite direction of the number being subtracted.
Subtracting a positive decimal moves you left toward smaller values, while subtracting a negative decimal turns you around to move right toward larger values.