story book has 280 pages, and Xiaohong reads 49 pages every day for 3 days. How many pages should she start reading on the fourth day?
一本故事书280页，小红每天看49页，看了3天，她第四天应从多少页看起．
<gadget id="calculator">49 * 3</gadget>
<output>147</output>

<gadget id="calculator">147 + 1</gadget>
<output>148</output>

<result>148</result>