Chopping arithmetic

Question

I would like to use chopping arithmetic for 3 digit chopping for the following:

$a)\pi$ and $b) 456788.1234567$

My guess is that it is $3.141$ and $456788.123$, but my book says the pi after chopping is $3.14$. I'm wondering if that's right since if I used same logic for a big number, like my second example, I'd get $456$, which is really different.

Answer 1

The answer for b) is 456000.
1) Count three digits including the first.
2) Keep the decimal point in the same place relative to the first digit.