Alyssa spent half of her allowance going to the movies. She washed the family car and earned 8 dollars. What is her weekly allowance if she ended with 12 dollars ?
<gadget id="calculator">12 - 8</gadget>
<output>4</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<result>8</result>