You might be referring to decimal places
(7 & 10), bc 10-7=3 and 10+7=17
Mathspapa a website that will help.
So time = distance/speed
515/216 = 2.38 min
in mixed number , 2 whole 83/216 !
In general this property looks like
a*1 = a.
This is identity property of multiplication, or multiplicative identity property.
