# Revision history [back]

### Why is 3e1 not equivalent to 30?

I thought that 3e1 is completely equivalent to 30. However, it is not:

sage: (1/30).n(digits=30)
0.0333333333333333333333333333333
sage: (1/3e1).n(digits=30)
0.0333333333333333328707404064062


Then I thought that 3e1 is always 53-bit real number or something like that. But I was wrong again:

sage: 1/3e1.n(digits=30)
0.0333333333333333333333333333333


Now I am just confused. Is this a bug? If not, how should I understand the second input above, and where can I find it documented? (Sage 5.0)

 2 retagged FrédéricC 2384 ●3 ●27 ●48

### Why is 3e1 not equivalent to 30?

I thought that 3e1 is completely equivalent to 30. However, it is not:

sage: (1/30).n(digits=30)
0.0333333333333333333333333333333
sage: (1/3e1).n(digits=30)
0.0333333333333333328707404064062


Then I thought that 3e1 is always 53-bit real number or something like that. But I was wrong again:

sage: 1/3e1.n(digits=30)
0.0333333333333333333333333333333


Now I am just confused. Is this a bug? If not, how should I understand the second input above, and where can I find it documented? (Sage 5.0)