So far, we have looked at simple repeating patterns, and basic number patterns. Now we are going to investigate ‘growing’ (or ‘increasing’) and ‘shrinking’ (or ‘decreasing’) patterns.
These patterns always have values that are changing by a fi xed certain amount.
By the end of this section you should: ● understand increasing and decreasing patterns ● be able to represent a pattern in a table ● be able to represent a pattern by drawing a graph
A value that changes (or varies) is called a variable.
Worked example 1 You receive a savings box as a birthday present on Sunday. The savings box already has €5 in it. From Monday, you plan to save €2 per day. (i) How much money will be in your savings box after 7 days? (ii) Identify the variables in this situation.
Solution (i)
(ii)
Drawing a graph of a pattern Sometimes it is helpful to draw a graph of a pattern to help us understand what is happening.
Worked example 2
John sends two messages from his mobile phone every day. Draw a graph to show the total amount of messages John sends in fi ve days.
Solution
Section A Introducing concepts and building skills