There are 8 red pens in Maria's desk drawer. There are 10 more black pens than red pens. There are also 7 more blue pens than red pens. How many pens are there in all?
Maria has 8 + 10 = 
<gadget id="calculator">8+10</gadget>
<output>18</output>
18 black pens.
Maria has 8 + 7 = 
<gadget id="calculator">8+7</gadget>
<output>15</output>
15 blue pens.
Maria has 8 + 18 + 15 = 
<gadget id="calculator">8+18+15</gadget>
<output>41</output>
41 pens in total.

<result>41</result>