Interesting P.3 Maths

[chin]

Oh, shoot! I can't convert mile to km and vice versa 

Well, the story was like this. We were hiking in Sai Kong. There was a sign that says something like 3.5 km to somewhere, and she asked how many miles is 3.5 km. I told her 1 mile is about 1.6km, and she couldn't estimate in her head how many miles is 3.5 km given the 1.6 ratio. I think for an adult, this is unacceptable.