Subtracting Scientific Notation: 3.3e-3 minus 9.4e-4

Published on March 27, 2026

Pre-Algebra

Evaluate the difference between two numbers in scientific notation, 3.3 x 10^-3 and 9.4 x 10^-4, and express the final answer in standard scientific notation.

Question

Answer

The problem asks to evaluate the expression and express the answer in scientific notation.
To subtract these two numbers, we need to have the same power of 10 for both terms. We can convert one of the terms so that both have the power of or both have the power of .
Method 1: Convert to
We want to express as a multiple of .
Since , we have:
Now, substitute this back into the original expression:
Factor out :
Calculate the difference:
So the result is:
This is already in scientific notation since .
Method 2: Convert to
We want to express as a multiple of .
Since , we have:
Now, substitute this back into the original expression:
Factor out :
Calculate the difference:
So the result is:
We need to express this in scientific notation, where the coefficient must be between 1 and 10 (inclusive of 1, exclusive of 10).
Substitute this back:
Both methods yield the same result.
The evaluation of the expression in scientific notation is: