Question

The speed of light is estimated at 186,000 miles per second rounded to the nearest thousand miles per second.

Answer 1

It was rounding to the nearest THOUSAND.

We are looking at the thousands place, keep that in mind.

Remember: everything 5 and above is rounded up, everything below 5 is rounded down.

186,789 is above 500, it is rounded to 187,000

186,899 is above 500, it is rounded to 187,000

185,990 is above 500, it is rounded to 186,000

and 185,190 is below 500, it is rounded to 185,000

Only one matches the criteria of the question:

185,990 is above 500, it is rounded to 186,000

therefore the answer is 185,990 miles per second

Have a fantastic day!