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Look to see whether $a$ and $b$ are odd or even. If the are both the same keep track of $0$. If they are different keep track of $1$.

If either $a$ or $b$ are odd subtract one; if even do nothing.

Divide $a$ and $b$ by $2$.

Repeat until done.

.....

Example $57 XOR 92$.

$57$ is odd $92$ is even: $**********1$

$(57-1)\div 2 = 28$. $92\div 2=46$. Both even: $*********01$

$14, 23$: One odd, the other even: $***********101$

$14\to 7$ and $23\to 22 \to 11$. Both odd: $*******0101$

$7\to 6\to 3$ and $11\to 10\to 5$. Both odd: $******00101$

$3\to 2\to 1$ and $5\to 4\to 2$. Different: $******100101$

$1\to 0$ and $4\to 1$. Different: $*******1100101$

$0$ adn $1\to 0$. Same and we are done:

$57 XOR 92 = 1100101$ or in decimal:

$1 + 0 + 4 +0 + 0 + 32 + 64 = 101$.

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Ross Millikin says it might be easier to go from the higher powers of two down.

Let's see.

$57XOR 92$.

Smallest power of $2$ larger than both is $128$ and both are smaller so that's a leading $0$ (doesn't) count.

Next power is $64$ and $57 < 64 < 92$. They are on different sides. Count it. $1_2$ or $64$.

Subtract $64 $ from $92$ to get $28$.

Next power is $32$. $28 < 32 < 57$. Different sides count that. $11_2$ or $64+32 = 96$.

Subtract $32$ from $57$ to get $25$.

Next power is $16$. $16 < 25< 28$. Both on same side. Don't count it. $110_2$ or $96$.

Subtract $16$ from both to the $9$ and $12$.

Next power is $8$. $8 < 9 < 12$. Same side. Don't count. $1100_2$ or $96$.

Subtract $8$ to get $1$ and $4$

Nex power is $4$. $1< 4= 4$. Equality is the cutoff points so they are considered different sides so so Count it. $11001_2$ or $96+4 = 100$.

Subtract $4$ from $4$ to get $0$

Next power is $2$. $0<1<2$ Same. $110010_2$ or $100$.

Last power is $1$. $0< 1=1$ Different. $1100101_2$ or $100 + 1 =101$

And we are done.

Was that easier? ..... I have to admit it had its charms.