The sum of an arithmetic series
Mathematics · Grade 11 · about 40 minutes
Derive the sum of the first n terms by pairing the first with the last, and use it on a rising list, a falling list and the first 20 counting numbers.
Sign in to read this lesson
Lessons are for learners and teachers with an account. Browsing the curriculum — subjects, strands and what each sub-strand covers — stays open to everyone.
- 9 sections of explanation, worked examples and diagrams
- 1 practice task with hints and worked answers
- A quiz that marks itself as you go
- Your progress kept across every subject you take
Other lessons in this sub-strand
- A rule for the nth term
- Arithmetic sequences
- The nth term of an arithmetic sequence
- Two terms determine the sequence
- The sum of an arithmetic series
- Geometric sequences
- The nth term of a geometric sequence
- The sum of a finite geometric series
- Sum to infinity
- Savings, seats and a light interval
- A fixed amount or a fixed percent