What is the pattern of 5 10 20 40

Question

This math is from the 5 th grade but my daughter does not understand it and is having a hard time

Answer 1

It is times 2 or you double the previous number .

5*2=10

10*2=20

20*2=40

Answer 2

If you look at this as in a sequence of numbers, then

a₁=5 = 2⁰*5

a₂=10=2¹*5

a₃=20=2²*5

....

a_n=5*2^n-1, n=1,2,3,...

Geometric progression with q=2.