The 3 is in the ten thousands place. So the question is whether to keep the three or to round the 3 up to 4.
The 2 in the thousands place will determine if you keep the 3 or round it up to 4. The 2 is closer to zero than to 10 so the 2 is changed to zero not 10. So the 3 stays a three.
Think about climbing a mountain when a storm comes up If you are half way up the mountain or higher you will climb up to the top.
So, for ( 5,6,7,8,9 ) round up to the next highest number.
If you are less than half way go back down the mountain to where you started. ( 0,1,2,3,4)