Jack sews 3 shirts for each of his 3 kids. He sews 7 buttons in each shirt. How many buttons must Jack use for all the shirts?
The total number of shirts for all his kids is 3 * 3 = 
<gadget id="calculator">3*3</gadget>
<output>9</output>
9 shirts.
The total number of needed buttons is 9 * 7 = 
<gadget id="calculator">9*7</gadget>
<output>63</output>
63 buttons.

<result>63</result>