In 8,157 the digit ‘8’ stands for 8 × ___
Make a place value diagram:
thousands 
Hundreds 
Tens 
Ones 

Digit 
8 
1 
5 
7 
Value of 1 
(1,000) 
(100) 
(10) 
(1) 
Value of digit 
8,000 
100 
50 
7 
So the answer is 1000