CK-12 Foundation
Ck 12: Analysis: Problem Solving With Series Sums
[Free Registration/Login may be required to access all resource tools.] More on calculating the partial sums of arithmetic series.
Khan Academy
Khan Academy: Sums of Consecutive Integers
Practice finding the nth number in a sequence of consecutive numbers based on the sum. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Math Notes and Math Tests
Pre Calculus Note: Arithmetic Sequences and Partial Sums [Pdf]
The tutorial discusses sequences and series. Students learn about arithmetic sequences, geometric sequences, partial sums, and infinite geometric series. The resource consists of class notes and examples with solutions.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Progresiones
This interactive unit introduces the concepts of arithmetic and geometric progression. It shows how to obtain the terms of a progression, its general term and the sum of the terms.