<?php
$values = [ -8.5, -8.45, 8.45, 8.5 ];

foreach (RoundingMode::cases() as $mode) {
    printf( '%20s: ', $mode->name );

    foreach ($values as $value) {
        printf( '%5s', round($value, 1, $mode) );
    }
    foreach ($values as $value) {
        printf( '%5s', round($value, 0, $mode) );
    }
    echo "\n";
}
Output
HalfAwayFromZero: -8.5 -8.5 8.5 8.5 -9 -8 8 9 HalfTowardsZero: -8.5 -8.4 8.4 8.5 -8 -8 8 8 HalfEven: -8.5 -8.4 8.4 8.5 -8 -8 8 8 HalfOdd: -8.5 -8.5 8.5 8.5 -9 -8 8 9 TowardsZero: -8.5 -8.4 8.4 8.5 -8 -8 8 8 AwayFromZero: -8.5 -8.5 8.5 8.5 -9 -9 9 9 NegativeInfinity: -8.5 -8.5 8.4 8.5 -9 -9 8 8 PositiveInfinity: -8.5 -8.4 8.5 8.5 -8 -8 9 9