Work the coefficients, work the powers — then check the answer is still IN scientific notation. Free printable worksheets.
If they get stuck
The answer key prints on a separate page.
Multiplying two numbers in scientific notation is two moves that do not interfere with each other: multiply the coefficients, and add the exponents. Dividing is the same with the other two operations. A student who does both of those gets a true statement about two thirds of the time, and that is the problem — the other third is true and is not an answer.
5 × 10³ times 4 × 10² is 20 × 10⁵. That is exactly the right quantity, and it is not written in scientific notation, because the notation has one rule: the coefficient sits at 1 or above and below 10. The answer is 2 × 10⁶. Dividing has the mirror case, where the coefficient falls under 1 and the exponent goes down instead.
One question from a sheet like this one, worked a step at a time — with a sentence saying what just happened and why.
Multiplying and dividing in scientific notation, step by step