81 rounded to the nearest 10 is 80
80
You would round it down... to 80.
80
81.0
80
The answer depends on what is meant by "the nearest decimal"
Round 412 nearest 10? Answer: 400 Reason: You play with last 2 digits of 412 (because he asked to round nearest 10; i.e. 12, now 11-14 is nearest to 10 so round to 10. So, 412 nearest to 10 is then 400.
Round 42,199,279 to the nearest 10 million.
Tio the nearest 10, it is 0.
As it ends with a five, it will round up, so 30 is the nearest 10.
Round 15 to the nearest 10 would be 20, as it is closer to 20 than 10.