Marie has 4 notebooks with 20 stamps each. She also has two binders with 50 stamps each. If she decides to only keep 1/4 of the stamps, how many stamps can she give away?
Marie has 4 x 20 = 
<gadget id="calculator">4*20</gadget>
<output>80</output>
80 stamps from her notebooks.
And she has 2 x 50 = 
<gadget id="calculator">2*50</gadget>
<output>100</output>
100 stamps from her binders.
So she has a total of 80 + 100 = 
<gadget id="calculator">80+100</gadget>
<output>180</output>
180 stamps.
Marie decided to keep 180 x 1/4 = 
<gadget id="calculator">180*1/4</gadget>
<output>45</output>
45 stamps only.
Therefore, she can give away 180 - 45 = 
<gadget id="calculator">180-45</gadget>
<output>135</output>
135 stamps.

<result>135</result>