![]() In fact, phone numbers aren't really just numbers because a leading zero can be important, as they can contain other characters – for example, +64 extn. One place this comes up is with phone numbers if you type 027555555 into a spreadsheet as a number, it will come up as 27555555, but as text the 0 can be displayed. ![]() if a cell starts with an inverted comma in Excel, it is treated as text rather than a number. You may have encountered this distinction in a spreadsheet e.g. ![]() Note that the text "358" is treated as 3 characters in ASCII, which may be confusing, as the text "358" is different to the number 358! You could write a word out using this code, and if you give it to someone else, they should be able to decode it exactly. The letter "o" has the pattern "01101111". example, the letter "c" (lower case) in the table has the pattern "01100011" (the 0 at the front is just extra padding to make it up to 8 bits). Here is a table that shows the patterns of bits that ASCII uses for each of the characters. Where possible, we prefer to deal with full bytes (8 bits) on a computer, this is why ASCII has an extra wasted bit. However, the left-most bit in each 8-bit pattern is a 0, meaning there are still only 128 possible patterns. ![]() In the previous section, we explained what happens when the number of dots was increased by 1 (remember that a dot in Braille is effectively a bit).Ĭan you explain how we knew that if 6 bits is enough to represent 64 characters, then 7 bits must be enough to represent 128 characters?Įach pattern in ASCII is usually stored in 8 bits, with one wasted bit, rather than 7 bits. ![]()
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