Lesson: Arithmetic Series Mathematics

In this lesson, we will learn how to calculate the sum of the terms in an arithmetic sequence with a definite number of terms.

Lesson Plan

Objectives

Students will be able to

recognize the formula for the sum of an arithmetic sequence in terms of the first and last terms,
recognize the formula for the sum of an arithmetic sequence in terms of its first term and common difference,
find the sum of arithmetic sequences with a given number of terms, including a given range of terms, and examples where you know the first and last terms, and the first term and the common difference (or have the information to calculate these),
solve applied problems, including finding the number of terms given the sum and other necessary information.

Prerequisites

Students should already be familiar with

working with arithmetic sequences, including finding terms and general terms, working with formulas, and solving related problems.

Exclusions

Students will not cover

any series that are not arithmetic.

Lesson Video

Lesson Explainer

Sample Question Videos

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Lesson Worksheet

Q1:

Find the number of terms in the arithmetic sequence whose first term is 11 and last term is 81, where the sum of all the terms is 506.

Q2:

Find the number of terms for which the sum of the sequence is 0.

Q3:

The house numbers on one side of a street are . Find the house number where the sum of the numbers before it is equal to the sum of the numbers after it.