Will format the given number by $precision and separated by $separator.

numberFormatPrecision.php

<?php

/**
 * numberFormatPrecision
 *
 * Will format the given number by $precision and separated by $separator.
 *
 * @param string|int|float $number
 * @param int $precision
 * @param string $separator
 * @return string
 */
function numberFormatPrecision($number, $precision = 2, $separator = '.')
{
    $numberParts = explode($separator, $number);
    $response = $numberParts[0];
    if (count($numberParts) > 1) {
        $response .= $separator;
        $response .= substr($numberParts[1], 0, $precision);
    }
    return $response;
}