So Many Sums

In this addition each letter stands for a different digit, with S standing for 3. What is the value of YxO?
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Problem



In this addition, each letter stands for a different digit, with $S$ standing for 3.

What is the value of $Y\times O$?

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So Many Sums



If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.