999*778+333*666.
999*778+333*666．
<gadget id="calculator">999 * 778</gadget>
<output>777_222</output>

<gadget id="calculator">333 * 666</gadget>
<output>221_778</output>

<gadget id="calculator">777_222 + 221_778</gadget>
<output>999_000</output>

<result>999_000</result>