Understanding 3 Digits of Accuracy in Calculus Problems

[afr123]

I'm refreshing my knowledge of calculus and ran into this problem while working on limits.

"Find∗ the value of each of the indicated limits to at least 3 digits of accuracy by evaluating f(x) at various values, or state that the limit does not exist (DNE)."

My problem is with "at least 3 digits of accuracy." If I type in an answer like 6.78, it says I'm wrong. If I type in the answer 6.778, it says I'm right. 6.78 has 3 significant digits though, so shouldn't that work?

It doesn't say 3 digits after the decimal point, it says "3 digits of accuracy." Isn't that referring to having 3 significant digits?

 

[Mark44]

IMO they are being sloppy by saying "digits of accuracy." To be clearer they should have phrased it as "three decimal places."