Martha has been collecting shells since she turned 5 years old, every month she collects one shell. By her 10th birthday, how many shells will Martha have collected?
In 12 months of the year, Martha collects 12 * 1 = 
<gadget id="calculator">12*1</gadget>
<output>12</output>
12 shells.
From her 5th to her 10th birthday, 10 - 5 = 
<gadget id="calculator">10-5</gadget>
<output>5</output>
5 years have passed.
During the 5 years that have passed, Martha has collected 12 * 5 = 
<gadget id="calculator">12*5</gadget>
<output>60</output>
60 shells.

<result>60</result>