Answer
ten-millions place
Work Step by Step
$\underset\uparrow51,682,700$
Starting from the left, each set of 3 numbers is a period.
$\ \ \ \ \underbrace{51},\ \ \ \underbrace{682},\ \ \ \ \underbrace{700}$
millions;thousands;ones
Within each period the place values, from the left, are ones, tens, hundreds.
Since the 5 is in the tens place in the millions period, 5 is in the ten-millions place.
