7. The answer is simply to round DOWN half the difference (or halve the difference minus one)
No. Example: The difference of 2/5 & 1/3: 2/5 - 1/3 = 1/15 ∈ ℚ (is a rational number) ∉ ℕ (is not a natural number).
Yes.
Not necessarily. The difference between a = 7 & b = 7 is 0, and that is not a natural number.
A natural number is a counting number, such as 1, 2, 3. There are also known as whole numbers and integers. They can be infinitely large. A real number is a number, possibly a natural number, but more possibly not, because there are an infinite number of real numbers that lie between any two natural numbers, such as 1, 1.1, 1.11, 1.111, 111112, etc, ad infinitum. Real numbers can also be infinitely large.
Difference of two odd numbers is an even number. Adding an even number changes nothing.
No. For two reasons: 1) Negative numbers are not natural numbers 2) All natural numbers are rational numbers but the square root of 6 is an irrational number and thus cannot be a natural number.
The difference of their cubes is 4.
No, since 2 is not divisible by three in the natural numbers.
No. 5 and 2 are real numbers. Their difference, 3, is a rational number.
Yes, the difference of two whole numbers is always a whole number.
An even number.