One meatball sub sandwich contains 4 meatballs.  Sidney ordered 3 less than ten meatball sub sandwiches. Then Mark ate 4 of Sidney's meatball sub sandwiches. So Sidney ordered another three sub sandwiches.  How many meatballs were in the sub sandwiches that remained?
3 less than ten meatball sub sandwiches is 10-3=
<gadget id="calculator">10-3</gadget>
<output>7</output>
7 sub sandwiches.
After Mark ate 4 of Sidney's meatball sub sandwiches, 7-4=
<gadget id="calculator">7-4</gadget>
<output>3</output>
3 remained.
Finally, after Sidney ordered three more sub sandwiches, there were a total of 3+3=
<gadget id="calculator">3+3</gadget>
<output>6</output>
6 sub sandwiches.
If each sub sandwich has 4 meatballs, then the remaining sub sandwiches contain a total of 6*4=
<gadget id="calculator">6*4</gadget>
<output>24</output>
24 meatballs.

<result>24</result>