Grade 8 Subtracting Numbers in Scientific Notation
Subtracting in scientific notation for grade 8 — give both numbers the same power of ten, then subtract the coefficients. Sixteen problems with key.
Subtract. Give both numbers the same power of 10 first, then write the answer in scientific notation.
- 1.(3.3 x 10^3) - (2.6 x 10^3) =
- 2.(8.3 x 10^6) - (3.0 x 10^5) =
- 3.(7.4 x 10^6) - (3.9 x 10^5) =
- 4.(7.2 x 10^9) - (5.6 x 10^8) =
- 5.(7.2 x 10^3) - (3.4 x 10^2) =
- 6.(6.5 x 10^4) - (7.0 x 10^3) =
- 7.(1.8 x 10^3) - (3.6 x 10^2) =
- 8.(7.2 x 10^9) - (1.4 x 10^9) =
- 9.(7.9 x 10^9) - (8.7 x 10^8) =
- 10.(1.4 x 10^5) - (3.9 x 10^4) =
- 11.(6.6 x 10^4) - (8.8 x 10^3) =
- 12.(8.7 x 10^4) - (1.9 x 10^4) =
- 13.(8.1 x 10^7) - (6.4 x 10^6) =
- 14.(9.5 x 10^2) - (8.0 x 10^2) =
- 15.(3.8 x 10^7) - (2.7 x 10^6) =
- 16.(5.0 x 10^9) - (1.2 x 10^8) =
What this worksheet covers
Sixteen subtraction problems fill the page, and the complete key sits behind them in the same PDF. Within that, the expressions carry exponents, including the zero and negative cases that break the "repeated multiplication" reading; the operands are decimals rather than whole numbers. Grade 8, Expressions & Equations, Common Core 8.EE.4: that is the exact slot this page fills.
Skills practiced
At this point in the sequence, work in subtraction is really about subtraction as adding the additive inverse. Working the page asks a student to keep decimal points aligned rather than right-aligning digits out of habit; apply exponent properties instead of expanding every term. Consistency across the page matters more than any single answer on it.
How to use this worksheet
Work it without a calculator. Every problem on this sheet is designed to be done by hand, and reaching for a calculator at grade 8 skips exactly the reasoning being built. Date the sheet before filing it. A page from six weeks ago is the cheapest evidence you have that something is sticking.
One mistake to watch for
A whole number minus a decimal is misaligned: 6 − 2.75 = 4.75 or 3.25.
The whole number has no decimal point to align to, so digits are pushed to the right edge instead.
Write 6 as 6.00 before starting. The placeholder zeros make the columns unambiguous.
Related worksheets
Also aligned to 8.EE.4
The same standard from a different angle. Worth reaching for when the skill needs another pass without repeating the identical page.
- Grade 8 Adding Numbers in Scientific Notation — grade 8, 16 problems
- Grade 8 Multiplying Numbers in Scientific Notation — grade 8, 16 problems
A step either side
The same topic one grade down and one grade up — the easier sheet is often the faster fix when this one is not landing.
- Grade 7 Subtracting Rational Numbers — grade 7, 20 problems
Free to download, free to print, and free to photocopy for a whole class — this subtraction sheet and its key are one PDF, aimed at subtraction as adding the additive inverse.