Well first you have to find the unit rate, or how many "p" each pencil costs. So you take 54 and divide it by 6, and you get 9. So each pencil costs 9 p, so you take 9 and multiply it by 8. That gets you 72, so 8 pencils cost 72p.
First you have to put them both into fractions.
6/54 and 8/X
X being the value your trying to find. So your going to cross multiply and divide. 8 • 54 and then divided by 6. 8 • 54= 432. Then 432 divided by 6 equals 72.
