The @for directive adds styles in a loop, very similar to a for loop in JavaScript. @for is used in two ways: "start through end" or "start to end". The main difference is that "start to end" excludes the end number, and "start through end" includes the end number. Here's a start through end example:

@for $i from 1 through 12 {
.col-#{$i} { width: 100%/12 * $i; }
}

The #{$i} part is the syntax to combine a variable (i) with text to make a string. When the Sass file is converted to CSS, it looks like this:

.col-1 {
  width: 8.33333%;
}

.col-2 {
  width: 16.66667%;
}

...

.col-12 {
  width: 100%;
}

This is a powerful way to create a grid layout. Now you have twelve options for column widths available as CSS classes.

Write a @for directive that takes a variable $j that goes from 1 to 6. It should create 5 classes called .text-1 to .text-5 where each has a font-size set to 10px multiplied by the index.

```yml tests: - text: Your code should use the @for directive. testString: 'assert(code.match(/@for /g), "Your code should use the @for directive.");' - text: Your .text-1 class should have a font-size of 10px. testString: 'assert($(".text-1").css("font-size") == "10px", "Your .text-1 class should have a font-size of 10px.");' - text: Your .text-2 class should have a font-size of 20px. testString: 'assert($(".text-2").css("font-size") == "20px", "Your .text-2 class should have a font-size of 20px.");' - text: Your .text-3 class should have a font-size of 30px. testString: 'assert($(".text-3").css("font-size") == "30px", "Your .text-3 class should have a font-size of 30px.");' - text: Your .text-4 class should have a font-size of 40px. testString: 'assert($(".text-4").css("font-size") == "40px", "Your .text-4 class should have a font-size of 40px.");' - text: Your .text-5 class should have a font-size of 50px. testString: 'assert($(".text-5").css("font-size") == "50px", "Your .text-5 class should have a font-size of 50px.");' ```