How to display number to two decimal places in bash function

Question

How should I take a number that is in hundreths of seconds and display it in seconds to two decimal places? Psuedo code to follow the dTime function I am not sure about but you'll get what I'm aiming for I think.

function time {
    echo "$(date +%N)/10000000"
}

function dTime {
    echo "($1/100).(${$1:${#1}-3:${#1}-1})"
}

T=$time
sleep 2
T=$dTime T

Answer 1

Below can be done for 2 decimal precision ,

echo $T | bc -l | xargs printf "%.2f"

Answer 2

Bash has a printf function built in:

printf "%0.2f\n" $T