Question 1154516
<br>
Multiply the original measurement by "unit fractions" which change the units without changing the measurement.<br><pre>
                 5280 feet      1 meter      1 decameter
   25.3 miles * ----------- * ----------- * -------------
                  1 mile       3.28 feet      10 meters<br></pre>
With that multiplication, the units cancel, leaving the measurement in decameters.  Since in each fraction the numerator and denominator are equivalent measurements, each fraction has the value 1; so the multiplications do not change the actual measurement.<br>
{{{(25.3*5280*1*1)/(1*3.28*10)}}}<br>
Use a calculator....<br>