All of the numbers written on the right of the equal (=) sign above are meant to be read as decimal numbers. Obviously (81) can’t be an octal number, since we don’t have a digit 8 in the octal system.
The reason for stressing this point is that when we are discussing two number systems it is necessary to be absolutely clear how a particular number is to be read. To tell the truth, we’ve been a little sloppy in writing such expressions as 3(81) without the decimal subscript. But 310(8110) is a rather clumsy expression, isn’t it? So we shall rely on you to remember that a number with no subscript is always meant to be read as a decimal number.
Now return to Page 236 and choose the other answer.
