Decimal notation describes numbers using the digits 1 through 10. Binary notation describes them using just two digits, 1 and 0, where each bit in a string represents a power of 2. The right-most bit ...

These are decimal numbers, and dots above some of the digits make them recurring decimals. One dot means the digit under it repeats infinitely. In other words, it goes on forever (and ever and ever).

Let’s see what Jerry and Albert are buying for their holiday. Looking good! We should work out how much money they’ll need. Let’s make a rough estimate by rounding the costs to the nearest pound.