Question

rick wants to compare 87.421 and 91.396. what might happen if he compares the 421 thousandths and the 396 thousandths first?

Answer 1

If the 432 thousandths and 396 thousandths got compared first, it would sound like the 87.421 should be greater, but its not, the 91.396 is.
But with the thousandths place being compared here, the .421 would be greater, therefore that being called the greater number. 

-Hope this helped