Computes the sum of six types of mathematical series: arithmetic, geometric, natural numbers (1+2+…+n), perfect squares, perfect cubes, and custom user-entered values. Each mode displays its closed-form formula and a preview of the first few terms, making it educational as well as practical for quick summation tasks.
Common Use Cases
- Sum an arithmetic sequence for a homework problem
- Find the total value of a geometric savings plan
- Verify the formula for sum of squares: n(n+1)(2n+1)/6
- Quickly add up a custom list of numbers
Series Types & Formulas
| Type | Formula | Parameters |
| Arithmetic | Sₙ = n/2 × (2a + (n−1)d) | First term a, common difference d, n terms |
| Geometric | Sₙ = a × (1 − rⁿ) / (1 − r) | First term a, common ratio r, n terms |
| 1+2+…+n | Sₙ = n(n+1) / 2 | Enter n only |
| 1²+2²+…+n² | Sₙ = n(n+1)(2n+1) / 6 | Enter n only |
| 1³+2³+…+n³ | Sₙ = [n(n+1)/2]² | Enter n only |
| Custom | S = Σ all entered values | Enter numbers separated by commas or spaces |
How to Use
- Select a series type from the chip buttons.
- The relevant formula is displayed in the formula box below the chips.
- Enter the required parameters for the chosen type.
- Click Calculate Sum — the result appears with a preview of the first few terms.
Tips & Notes
Note: For Geometric series, ratio r = 1 uses the simplified formula S = a × n.
Note: The Custom mode accepts any mix of integers and decimals — useful for ad-hoc totals.
Note: Term preview shows the first 8 values; if there are more, the pill shows how many are hidden.
