Representation of floats



I'm sorry, but I have to try again. Let us compare.

Maxima 5.27.0
----------------

numer:true$
for k:1 thru 29 do print("k=",k,":  ",1/5^k)$

k= 1 :   0.2 
k= 2 :   0.04 
k= 3 :   0.008 
k= 4 :   0.0016 
k= 5 :   3.2000000000000003E-4 
k= 6 :   6.3999999999999997E-5 
k= 7 :   1.2799999999999999E-5 
k= 8 :   2.5600000000000001E-6 
k= 9 :   5.1200000000000003E-7 
k= 10 :   1.024E-7 
k= 11 :   2.0479999999999999E-8 
k= 12 :   4.0959999999999999E-9 
k= 13 :   8.1920000000000002E-10 
k= 14 :   1.6384E-10 
k= 15 :   3.2768000000000003E-11 
k= 16 :   6.5535999999999999E-12 
k= 17 :   1.3107200000000001E-12 
k= 18 :   2.6214400000000002E-13 
k= 19 :   5.2428799999999999E-14 
k= 20 :   1.0485759999999999E-14 
k= 21 :   2.0971519999999998E-15 
k= 22 :   4.1943040000000002E-16 
k= 23 :   8.3886080000000009E-17 
k= 24 :   1.6777216000000002E-17 
k= 25 :   3.3554432000000005E-18 
k= 26 :   6.7108864000000012E-19 
k= 27 :   1.3421772800000001E-19 
k= 28 :   2.6843545600000002E-20 
k= 29 :   5.3687091200000004E-21 


Firefox 11.0
------------

<html>
<body>
<p id="p"></p>
<script>
for(k=1;k<30;k++) 
document.getElementById("p").innerHTML+="k="+k+":  "+1/Math.pow(5,k)+"<br>";
</script>
</body>
</html>

k=1: 0.2
k=2: 0.04
k=3: 0.008
k=4: 0.0016
k=5: 0.00032
k=6: 0.000064
k=7: 0.0000128
k=8: 0.00000256
k=9: 5.12e-7
k=10: 1.024e-7
k=11: 2.048e-8
k=12: 4.096e-9
k=13: 8.192e-10
k=14: 1.6384e-10
k=15: 3.2768e-11
k=16: 6.5536e-12
k=17: 1.31072e-12
k=18: 2.62144e-13
k=19: 5.24288e-14
k=20: 1.048576e-14
k=21: 2.097152e-15
k=22: 4.194304e-16
k=23: 8.388608000000001e-17
k=24: 1.6777216000000002e-17
k=25: 3.3554431999999997e-18
k=26: 6.710886399999999e-19
k=27: 1.34217728e-19
k=28: 2.6843545600000002e-20
k=29: 5.3687091200000004e-21

=================================

I don't see: where is rounding? Firefox up to k=22 returns exact values