You can better try this way and let me know.
function wpb_adding_scripts() {
wp_enqueue_style( 'slider', get_stylesheet_directory_uri() . '/css/calculator.css');
wp_enqueue_script('jquery');
wp_enqueue_script('calculator_script', get_stylesheet_directory_uri() . '/js/calculator.js');
}
add_action( 'wp_enqueue_scripts', 'wpb_adding_scripts' );