The standard form of 28 is what?

The standard form (scientific notation) of 28 is:
2.8 × 10¹

In standard form, a number is written as:
a × 10?, where 1 ≤ a < 10

We move the decimal point one place to the left:
28 → 2.8

Since we moved it once, the power of 10 is 1.

Standard form is useful for writing very large or very small numbers in a simple way.

Thus, the standard form of 28 is 2.8 × 10¹.