Mao Mao, a little monkey from Class 3, Class 1 of the Animal School, was calculating a double-digit multiplication problem. He regarded the 4 in the unit digit of one of the multipliers as 1, and the product was 735. Xiao Le took this multiplier The number in the ones place is regarded as 8, and the result is 980. What is the correct number?
动物学校三1班的小猴毛毛在计算一道两位数乘两位数的题，把其中一个乘数个位上的4看成了1，得出的积为735，小乐把这个乘数个位上的数字看成了8，得到的结果是980，正确得数是多少？
<gadget id="calculator">35 * 24</gadget>
<output>840</output>

<result>840</result>