**1. What is the difference between natural numbers and whole numbers?**

Whole numbers include zero.

**2. What are irrational numbers?**

Irrational numbers are any numbers that cannot be written as a fraction. e.g. Numbers that never end on the calculator and have no pattern, such as 3.1415923565...

**3. What is the biggest multiple of 9?**

There is never a biggest ever multiple. Multiples form INFINITE sets that go on and on and on and on and ...

**4. Is "1" a prime number?**

No, "1" is a special number but it is not classed as a prime number.

**5. Is "2" a prime number?**

Yes, because 2 has only two factors i.e. 2 and 1, it is classed as a prime number.

**6. What is the reciprocal of 0?**

The reciprocal of zero is not defined because you cannot say how many times zero divides into anything.

**7. Can any number be written in standard form?**

Yes, any number however small or large can be written in standard form.