Php 列gridview yii2中的乘法

我如何从这样的模型中乘以两个属性

['value' => ('items.order_items_quantity' * 'items.order_items_initialPrice')],

[
    ...
    'value' => function($data) {
        return ($data->order_items_quantity * $data->order_items_initialPrice);
    }
]

[
    'attribute' => 'column1',
    'value' => function ($data, $key, $index, $column) {
        return $data->column1 * $data->column2;
    },
]