Yup, the amount of 0's is the exponent. for example 1000= 10^3, hope this helped :)
7623, 27.8, 76.9, and 8401 it is really simple just use a calculator........
1/5 is an expression that represents 1÷5= .2
Since the return decimal equivalent doesn't go on forever and has a finite end, this is a member of the rational number set.
Answer:
is one to one mapping, it is not onto mapping
Step-by-step explanation:

f₁(x) is one to one mapping
Let 
f₁(x) = f₁(y):
x₁³ = y₁³
f₁(x) is not onto mapping
Example: If f₁(x) = 7,
x₁³ = 7
![x_{1} = \sqrt[3]{7}](https://tex.z-dn.net/?f=x_%7B1%7D%20%3D%20%5Csqrt%5B3%5D%7B7%7D)
x₁ is not an element of Z
is one to one mapping, it is not onto mapping