Answer:
1010010001
Step-by-step explanation:
Keep dividing 657 by 2, and record the quotient and remainder
657
328,1
164,0
82,0
41,0
20,1
10,0
5,0
2,1
1,0
So chain the remainders from bottom up to get the binary number:
1010010001
Check:
1+16+128+512=657 checks.
