$4433.764 - 2211.993 - 1133.667 + 3377.442 = ?$

There is a number consisting of two digits. The digit in the units place is twice that in the tens place,and if $2$ is subtracted from the sum of the digits,the difference is equal to $1/6^{\text{th}}$ of the number. The number is:

$92^{2} - 12^{2} = 3535 + ?$

$2 \times 256 \times ? = 8^{2} \times 10^{2} \times 2$

$1601 \times 198 \div 49 - 1399 + 3878 = ?$

$47 \times 251 - 13343 + 1547 = ?$