Start with 9 multiply by 5 the answer is 45 is bigger than 9 Ellens calculayions are correct but her rule doesn't always work for what numbers will Ellen's rule work? For what numbers will Ellen's rule not work

So, this rule is not applicable if the number b is less than 1.

Step-by-step explanation:

Ellen's Rule is

9 multiply by 5 the answer is 45 which is more than 9

This rule is generalised as

A x b > A if b is > 1

Here, A is 9 and b is 5 and it is more than 1 so, A x b = 45 > A

now

A x b < A if b is < 1

If b = 0.5, A = 9

9 x 0.5 = 4.5 < 9

So, this rule is not applicable if the number b is less than 1.