Hi Nan, this is what it says on the website for the first book:

1) When should my child start the series?

Life of Fred: Fractions is the first book in the series. It presupposes that the reader knows three things:

i) the addition tables What's 5 + 8?

ii) the multiplication tables What's 7 times 8?

iii) long division What's 6231 divided by 93?