Listing every factor of a number

Difficulty Stretch · Set pt3wvq

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1
List every factor of 71, smallest first, separated by commas.
2
List every factor of 29, smallest first, separated by commas.
3
List every factor of 144, smallest first, separated by commas.
4
List every factor of 90, smallest first, separated by commas.
5
List every factor of 143, smallest first, separated by commas.
6
List every factor of 126, smallest first, separated by commas.
7
List every factor of 13, smallest first, separated by commas.
8
List every factor of 63, smallest first, separated by commas.
9
List every factor of 98, smallest first, separated by commas.
10
List every factor of 87, smallest first, separated by commas.
11
List every factor of 37, smallest first, separated by commas.
12
List every factor of 51, smallest first, separated by commas.
13
List every factor of 75, smallest first, separated by commas.
14
List every factor of 80, smallest first, separated by commas.
15
List every factor of 35, smallest first, separated by commas.
16
List every factor of 122, smallest first, separated by commas.
17
List every factor of 134, smallest first, separated by commas.
18
List every factor of 39, smallest first, separated by commas.
19
List every factor of 13, smallest first, separated by commas.
20
List every factor of 137, smallest first, separated by commas.

What is in this set

The numbers in this set run from 12 to 144.
48% of them have seven factors or fewer.
30% of them have more than seven factors.
A careful solution takes 8.8 written steps on average.
The mistake this set invites most often, in 77% 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 114 different ones, 48% — 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.