The checked keyword is used to control the overflow-checking
context for integral-type arithmetic operations and conversions. It can
be used as an operator or a statement according to the following forms.
This blog shows on how to use a Checked Operator in C#
checked
{
// Start of checked block
Byte b = 100;
b = (Byte) (b + 200); // This expression is checked for overflow.
}
// End of checked block