How can you tell when a pattern shows counting on by 10

If you see a zero in the end of a number it might be counting on by ten, the hint is most likely the zero. Let's say you had a question like: 10_30. If you see the zero, you can make sense out of it and try the tens times table. So add ten to 10 and bam! You found your answer

If you see a zero that means that you are counting by 10s For example: 10,20,30,40,50,60,70,80

They are the facts that mary is a citizen