# The Seventh Wave

Purpose

The purpose of this activity is to engage students in using mathematical strategies to solve a problem involving a sequence.

Achievement Objectives
NA3-3: Know counting sequences for whole numbers.
NA3-8: Connect members of sequential patterns with their ordinal position and use tables, graphs, and diagrams to find relationships between successive elements of number and spatial patterns.
Description of Mathematics

The background knowledge and skills that should be established before and/or during this activity are outlined in the diagram below:

Click to show example questions for each heading

This activity may be carried out with step by step guidance, or by allowing the student to follow their own method of solution. The approach should be chosen in sympathy with students' skills and depth of understanding.

Activity

Sam the surfer knows that the seventh wave in each set is the biggest. It is also the middle wave in each set.

Sam is surfing with five other surfers. To be safe, they each take a wave in turn. Sam takes the very first wave of the first set.

They are in the water long enough to surf every wave of ten sets. How many 'seventh waves' does Sam get?