Picking the High-Order Bit

From the above, it is easy to decide that 18, in binary, is 10010.

The leftmost bit (the high order bit) of a binary representation of an integer corresponds to the highest power of two that "fits" into the integer. For example:

Integer	Too Big	Best Fit	Too Small	Leftmost Bit
16	25=32	24=16	23=8	1 _ _ _ _
18	25=32	24=16	23=8	1 _ _ _ _
23	25=32	24=16	23=8	1 _ _ _ _
49	26=64	25=32	24=16	1 _ _ _ _ _
52	26=64	25=32	24=16	1 _ _ _ _ _
63	26=64	25=32	24=16	1 _ _ _ _ _
64	27=128	26=64	25=32	1 _ _ _ _ _ _