An archer needs to practice.  He intends to shoot 200 shots 4 days a week.  He is able to recover 20% of his arrows.  The arrows he uses cost $5.5 per arrow.  His team agrees to pay for 70% of the cost of his arrows.  How much does he spend for arrows a week?
He shoots 200*4=
<gadget id="calculator">200*4</gadget>
<output>800</output>
800 shots per week.
He can recover 800*.2=
<gadget id="calculator">800*.2</gadget>
<output>160</output>
160 of those arrows.
So he uses 800-160=
<gadget id="calculator">800-160</gadget>
<output>640</output>
640 arrows a week.
The cost for those arrows would come out to 640*5.5=$
<gadget id="calculator">640*5.5</gadget>
<output>3_520</output>
3520 per week.
His team pays for 3520*.7=$
<gadget id="calculator">3520*.7</gadget>
<output>2_464</output>
2464 of that.
So he has to pay 3520-2464=$
<gadget id="calculator">3520-2464</gadget>
<output>1_056</output>
1056 per week for arrows.

<result>1_056</result>