A piece of fabric, if you make 6 pairs of trousers, there will be 0.4 meters left; if you make 4 jackets, there will be 1 meter left. It is known that each jacket uses 0.4 meters more than each pair of trousers, so how many meters does this piece of fabric have?
一块布料，如果做6条裤子则剩下0.4米；如果做4件上衣则剩下1米．已知每件上衣比每条裤子多用0.4米，那么这块布料共有多少米？
<gadget id="calculator">0.4 * 4</gadget>
<output>1.6</output>

<gadget id="calculator">1 - 0.4</gadget>
<output>0.6</output>

<gadget id="calculator">1.6 + 0.6</gadget>
<output>2.2</output>

<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">2.2 / 2</gadget>
<output>1.1</output>

<gadget id="calculator">6 * 1.1</gadget>
<output>6.6</output>

<gadget id="calculator">6.6 + 0.4</gadget>
<output>7</output>

<result>7</result>