The number 9/10 belongs to the following sets:
1. Rational numbers: The number 9/10 can be expressed as a fraction and is therefore a rational number.
2. Real numbers: The set of real numbers includes rational and irrational numbers, and since 9/10 is a rational number, it is also a real number.
3. Integers: The set of integers includes whole numbers and their negatives. Although 9/10 is not an integer itself, it can be written as the fraction 9/10 or the decimal 0.9, which is very close to 1. Thus, it can be rounded up to the nearest integer, which is 1. Therefore, 9/10 can also be considered an integer in a broader sense.
4. Natural numbers: The set of natural numbers is a subset of whole numbers and includes positive integers only. Since 9/10 is not a positive integer, it does not belong to the set of natural numbers.
Therefore, the number 9/10 belongs to the sets of rational numbers, real numbers, and integers.