Flashback

Solve the following problem: Write $\mathrm{W}$ in the box if the answer is a whole number else write $\mathrm{X}$:

$100+58-72=$_____

Solve the following problem: Write $\mathrm{W}$ in the box if the answer is a whole number else write $\mathrm{X}$:

$262-\left(100+99+63\right)=$_____

What is the next number in the pattern? $123,234,345,$_____

The number represented by the shaded part of the given shape is _____.

Solve the following problem: Write $\mathrm{W}$ in the box if the answer is a whole number else write $\mathrm{X}$:

$834-900=$_____

Solve the following problem: Write $\mathrm{W}$ in the box if the answer is a whole number else write $\mathrm{X}$:

$1\times 101\times 1001=$_____