Subtract the largest power of 2 from 798 such that the difference is not negative.
2⁹ = 512 and 2¹⁰ = 1024, so the largest power of 2 smaller than 798 is 2⁹, and
798 = 512 + 286 = 2⁹ + 286
Repeat this process with the remainder, 286.
2⁸ = 256, so
286 = 256 + 30 = 2⁸ + 30
⇒ 798 = 2⁹ + 2⁸ + 30
2⁴ = 16 and 2⁵ = 32, so
30 = 16 + 14 = 2⁴ + 14
⇒ 798 = 2⁹ + 2⁸ + 2⁴ + 14
2³ = 8, so
14 = 8 + 6 = 2³ + 6
⇒ 798 = 2⁹ + 2⁸ + 2⁴ + 2³ + 6
2² = 4, so
6 = 4 + 2 = 2² + 2¹
⇒ 798 = 2⁹ + 2⁸ + 2⁴ + 2³ + 2² + 2¹
or more completely,
798 = 1×2⁹ + 1×2⁸ + 0×2⁷ + 0×2⁶ + 0×2⁵ + 1×2⁴ + 1×2³ + 1×2² + 1×2¹ + 0×2⁰
Then the base-2 representation of 798 is
11 0001 1110₂