- Since 4 is in the tenths place, 646.42 is between 646.4 and 646.5
- 646.45 is the midpoint between 646.4 (646.40) and 646.5 (646.50)
- As illustrated on the number line, 646.42 is less than the midpoint (646.45)
- Therefore, 646.42 rounded to the nearest tenth (one decimal place) = 646.4
%20with%20a%20number%20line.png "646.42 rounded to the nearest tenth (one decimal place) with a number line")
