Video Transcript
In July 1976, a Lockhead SR-71A set a record for jet speed at 2193.167 miles per hour. Round this speed to the nearest mile per hour.
This jet travels really fast — 2193.167 miles per hour. We wanna know what is the speed to the nearest mile per hour. So we need to check and see what number is in the units’ place for the mile per hour. This three is in the units’ place. Our units are written in miles. To see if we’re going to round this three up or keep it the same, we have to check what is to the right of our three.
In this case, if we’re working with units, if we’re working with our ones’ place, then we’ll check the 10s’ place to see how to round our three. If our 10s’ place is greater than or equal to five, we round up. If our 10s’ place is less than or equal to four, we round down.
In the 10s’ place in this problem, there is a one; that means we’ll round this number down. 2193.167 is rounded to 2193 miles per hour. We rounded this number down by keeping the three the same and removing the 167 1000ths. The Lockheed SR-71A record to the nearest mile per hour is 2193 miles per hour.
