Modify WooCommerce price for currency conversion and better decimal display

functions.php

<?php

    // define the raw_woocommerce_price callback
    function modify_price_for_currency ( $price, $product ) {

        global $post, $woocommerce;

        if( !$product  ) return $price;

        $new_price = $price*0.89;
        $whole = floor($new_price);      // 1
        $fraction = $new_price - $whole; // .25

        if( $fraction > 0 && $fraction <= 0.45 ) {
            $fraction = 0.45;
        } elseif( $fraction > 0.45 && $fraction <= 0.95 ) {
            $fraction = 0.95;
        } elseif( $fraction > 0.95 && $fraction <= 0.99 ) {
            $fraction = 0.99;
        } else {
            $fraction = 0;
        }

        return $whole + $fraction;
    }

    // add the filter
    add_filter('woocommerce_get_price', 'modify_price_for_currency', $product, 10, 2 );
    add_filter('woocommerce_get_regular_price', 'modify_price_for_currency', 10, 2 );
    add_filter('woocommerce_get_sale_price', 'modify_price_for_currency', 10, 2 );