---
title: Compound Assignment With Augmented Subtraction
---
## Compound Assignment With Augmented Subtraction

<!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds  -->
Computers read from left to right. So, using the '-=' operator means that the variable is subtracted by the number on the right, then the variable is assigned to the difference. Like so:

    var b = 10;
    b -= 4; // Now, 'b' is 6
