round to 2 decimals sh

Question

I would like to get two decimals after the dot in this expression: 7/2

#temperature equal 7
tempeture= `cat temperature`  
rate= expr $temperature/2  
echo "$rate"

I'm getting 3 and I want 3.50. thks

Answer 1

One way to round to two decimails would be to use the bc command and setting the scale variable equal to 2:

echo "scale=2; ($temperature/2)" | bc

You could also use printf like this:

printf "%.2f" $(($temperature/2))