$a=1.234; $x=1.2e4; $y=7E-10;
<?php $x=22.41; echo $x; ?>
<?php $a = 11.365; var_dump($a); ?>
<?php $a = 6.203; $b = 2.3e4; $c = 7E-10; var_dump($a); var_dump($b); var_dump($c); ?>