8th Grade · Expressions & Equations
Matching Exponents
8.EE.A.4
Definition
Adjusting numbers in scientific notation so their powers of ten are equal, which is required before adding or subtracting them.
Examples
- 4.2 × 105 + 3.0 × 104: rewrite 3.0 × 104 as 0.3 × 105, then add: 4.5 × 105.
- Multiplying and dividing do NOT need matching exponents — only adding and subtracting do.
Key rule
Make the exponents match first, then add or subtract the coefficients.
Memory hook
Match the powers of ten before adding.