The engineering team built a road with a length of 84 kilometers. It was originally planned to be completed in 28 days, but it was actually completed in 21 days. How much more kilometers were actually repaired per day than planned?
工程队修一条长为84千米的路，原计划28天完成，实际21天就完成了，实际每天比计划多修多少千米？
<gadget id="calculator">84 / 21</gadget>
<output>4</output>

<gadget id="calculator">84 / 28</gadget>
<output>3</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<result>1</result>