Adding three 3-digit numbers

Difficulty Stretch · Set r61y8y

Fill in what you can and press Check. Nothing you type is sent anywhere.

1
923533792+504
2
955887656+427
3
576729760+753
4
893539267+685
5
212535855+708
6
683806631+120
7
647408695+836
8
600296290+106
9
239510974+266
10
812855234+996
11
294866412+741
12
719446302+274
13
610784773+516
14
658899950+941
15
941484199+300
16
135385591+373
17
870548492+325
18
375814337+912
19
751728227+463
20
303440471+555

What is in this set

The numbers in this set run from 100 to 999.
Every problem in it will need a carry into the next column.
A careful solution takes 6 written steps on average.
The mistake this set invites most often, in 100% of the problems: only the first two addends were added — the third column never joined in.
Answers are a whole number.

Drawing 240 problems from this page produced 240 different ones, 100% — so a sheet of 20 is a new sheet almost every time.

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.