The three digit number is represented by ($x$  is units digit, $y$ is hundred digit, z is tenth digit)

Let the units digit is $=x$

Let the ten’s digit is $=z$

Let the hundred digit is $=y$

$\therefore$  the digit number is $=100\left(y\right)+10\left(z\right)+1\left(x\right)$

$=100y+10z+x$