Each question asks for the first four or five multiples of a number: the first five multiples of 6 are 6, 12, 18, 24 and 30. The count is stated in the question, so a student always knows when to stop.
Multiples are skip counting with the name it gets later. A student who can count by sixes can already answer these; what changes is the vocabulary, and that vocabulary is what fifth and sixth grade use when they start finding common multiples of two numbers.
The result of multiplying a number by a whole number. The multiples of 6 are 6, 12, 18, 24 and so on - what you say when you count by sixes.
Factors divide into a number; multiples are what it divides into. 6 is a factor of 24, and 24 is a multiple of 6. The two words describe the same relationship from opposite ends, which is why they are taught together.
Yes. The first multiple of 7 is 7, not 14. Some textbooks count zero as a multiple as well; these sheets start at the number, which is the common convention in elementary work.
Fourth grade, and again in fifth and sixth when least common multiples arrive.