Do you mean it doesn't display trailing zeroes in the decimals? You can add them using sprintf:

$num = 64;
$num = sprintf('%.2f', $num);
print($num, "\n");  # Prints 64.00
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Note that %f rounds:

$num = 123.456;
$num = sprintf('%.2f', $num);
print($num, "\n");  # Prints 123.46
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