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Straight-Line Graphs

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Summary

By using straight-line graphs to compare the price difference of two mobile phone deals, this area of KS4 maths is effectively illustrated in a video designed for use in class.

Dave thinks his pay-as-you-go mobile phone deal is a bargain, with 1000 texts and 600 minutes of talk time, for £20 per month. However, he did have to pay for the phone and Fran thinks he could have got a better deal going for an 18-month contract, with a free phone, but at £35 per month.

Dave speaks to some students to get their opinions on the matter, whilst Fran puts together straight-line graphs to compare each deal. It transpires that the pay-as-you-go deal is cheaper, but what happens when the 5p per day internet charge is added?

Fran produces more straight-line graphs to factor this in and to work out how often he can use the internet and still be better off.

Published : May 2010

15 mins

Series

Inside Maths

Roles

Secondary Pupil

Subjects

Secondary Maths

Number and algebra

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