Note:
1: tens
2: ones
.
1: tenths
5: hundredths
3: thousandths
7: ten-thousandths
You are solving for thousandths. Look at the number in the ten-thousandths place. It is a 7. Because 7 is greater than 5, you round up
12.1537 => 12.154
12.154 is your answer
hope this helps
