Answer:
10
Step-by-step explanation:
This is the answer because:
1) We always have to look at the rounding digit (this digit is located right next to the tens digit in this problem).
2) Since the ones digit is smaller than 5, it has to round down to 10. If the digit was 5 or greater, than it would be 20.
Therefore, the answer is 10.
Hope this helps! :D
