A bird eats 7 berries a day. Samuel has 5 birds. How many berries do Samuel's birds eat in 4 days?
A bird eats 7 x 4 = 
<gadget id="calculator">7*4</gadget>
<output>28</output>
28 berries in 4 days.
So, 5 birds can eat 28 x 5 = 
<gadget id="calculator">28*5</gadget>
<output>140</output>
140 berries in 4 days.

<result>140</result>