Here's how it works:

* Standard form (also called scientific notation) expresses a number as a product of a number between 1 and 10 (inclusive) and a power of 10.

* To get 0.34 into this form, move the decimal point one place to the right, giving us 3.4.

* Since we moved the decimal one place to the right, the power of 10 is -1 (moving the decimal to the right makes the number smaller, so the exponent is negative).

Therefore, 0.34 in standard form is 3.4 x 10⁻¹.