Num pad is faster than num row because you can use the thumb on zero, allowing you to use all 5 fingers without ever moving the hand.

However the secret to achieve true mad man number typing speeds is to use both hands. Num row is for the left hand. Num pad is for the right hand.

This can be optimized by positioning your left hand on 1 to prepare yourself for Benford’s Law which tells us that a majority of numbers start with 1.

Actual numbers also includes many zeros (but rarely starts with one). The fat zero key on num pad has room for two fingers, just saying.