Answer
The number is $26$.
Work Step by Step
Let
$x$ = the unknown number
Then
"twice a number" means $2x$
"sum of four and twice a number" means $4+2x$
Thus, the equation that represents the situation is:
$4+2x=56$
Subtract $4$ on both sides of the equation to obtain:
$2x=52$
Divide $2$ on both sides of the equation to obtain:
$x=\dfrac{52}{2}
\\x=26$
