Education Technology

Mathematics lessons for IB® Diploma Programme

Analysis and Approaches | Numbers and Algebra


Exploring Geometric Sequences

Activity Overview

Students explore geometric series by considering the effect of the value for the common ratio and first term using sliders.

Key Steps


Step 1

Students will explore geometric sequences graphically and numerically by varying the values of the common ratio. Clicking on the up or down arrow of the minimized slider while viewing a split screen of a graph and a spreadsheet makes this a dynamic activity.


Step 2

Changing the values of both of the variables, first term and common ratio, of a geometric sequence gives students a deeper understanding of their behavior. A spreadsheet of the terms is available on page 3.2 to investigate the behavior numerically.


Step 3

Students will examine the derivation of the sum of a finite geometric series and use it to solve several problems. Student will also use Mathboxes to calculate the cumulative sum of a sequence.