Listing every factor of a number

Difficulty Standard · Set fyiaas

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1
List every factor of 13, smallest first, separated by commas.
2
List every factor of 26, smallest first, separated by commas.
3
List every factor of 33, smallest first, separated by commas.
4
List every factor of 74, smallest first, separated by commas.
5
List every factor of 45, smallest first, separated by commas.
6
List every factor of 79, smallest first, separated by commas.
7
List every factor of 20, smallest first, separated by commas.
8
List every factor of 75, smallest first, separated by commas.
9
List every factor of 79, smallest first, separated by commas.
10
List every factor of 57, smallest first, separated by commas.
11
List every factor of 74, smallest first, separated by commas.
12
List every factor of 80, smallest first, separated by commas.
13
List every factor of 38, smallest first, separated by commas.
14
List every factor of 43, smallest first, separated by commas.
15
List every factor of 74, smallest first, separated by commas.
16
List every factor of 68, smallest first, separated by commas.
17
List every factor of 65, smallest first, separated by commas.
18
List every factor of 36, smallest first, separated by commas.
19
List every factor of 43, smallest first, separated by commas.
20
List every factor of 44, smallest first, separated by commas.

What is in this set

The numbers in this set run from 12 to 80.
49% of them have seven factors or fewer.
27% of them are prime.
A careful solution takes 7 written steps on average.
The mistake this set invites most often, in 73% of the problems: a number is always a factor of itself, and 1 is a factor of everything — both belong in the list.
Answers are a short answer exactly as the problem asks for it.

Drawing 240 problems from this page produced 65 different ones, 27% — so a sheet of 20 will come back to a problem you have seen — there are only so many sensible ones of this kind.

The same skill, harder or easier

We would put this in front of a grade 4 class. That is our judgement, not a standard, and it is printed here so you can disagree with it. Everything else we put in that year.