Marcus paid 45 cents for 2 pencils. At that rate, what would 8 pencils cost?

8 pencils will be $1.80

Because to get to 8 pencils to 2, you will have to multiply by 4, because 4 x 2=8. Then you multiply 8 by 45 cents, that equals 180 cents. And we know that $1 equals to 100 cents. Then you just put a decimal in between the 1 and 8, to make $1.80