Arithmetic and geometric series worksheet for Precalculus
Precalculus series use negative ratios and long arithmetic sums, given as the first few terms and the number of terms to add. These are the finite sums behind sigma notation and the infinite geometric series that come later.
Also taught in Algebra 2 and Algebra 1, each at its own level and with its own examples.
Not quite the one you need? Same words, different skill:
- Arithmetic Sequences (Precalculus). Adding the same amount each time.
- Sequences (Precalculus). A term, which term, or a formula for the nth term.
- Arithmetic Series (Precalculus). Adding up a sequence with a constant step.
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Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep
Sigma Prep · sigmaprep.io/worksheets Name Series Date Period Find each sum.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name SeriesAnswer keyVersion 3 Date Period Find each sum.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
Find the sum of the first 6 terms:
- First term 2, ratio -6 ÷ 2 = -3, six terms.
- S = 2(1 - (-3)⁶)/(1 - (-3)) = 2(1 - 729)/4.
- 2 × -728 ÷ 4 = -364.
The answer is .
Where students go wrong
Losing the sign of a negative ratio in the formula. With r = -3 the bottom is 1 - (-3) = 4, not -2, and (-3)⁶ is positive 729.
Also called summing a sequence.
What you can put on this worksheet
- The sum of an arithmetic series
- Find the sum of the first 7 terms: →
- The sum of a geometric series
- Find the sum of the first 4 terms: →
- Given the last term
- Find the sum: →
- In sigma notation, or to a last term
- Find the sum: →