Problems for children from different backgrounds
In different countries around the world, different symbols are used to mark the decimal part of the number and to separate the thousands. In Australia today we use a decimal point and a space (as a thousands separator), but until the 1970's the accepted notation was a comma as a thousands separator. Not only are different symbols used as decimal markers and thousands separators but they can also be used to convey completely different meanings, i.e. in some cultures a point is used to indicate multiplication. It is important to realise that children from other countries may be accustomed to different notation, making it difficult for them to read and understand numbers in the Australian classroom. Some variation is often also found within a country. The decimal point in Australia (and elsewhere) used to be above the line, but with widespread computer use they are now generally on the line, as in this resource. Below is a table giving an example of notation from several countries.
Difficulties in learning decimals (e.g. Reverse thinking) can also stem from differences in children's first language. For example, Asian language speakers have to make a special effort to indicate the presence of a 's' at the end of an English word as it is not their accustomed way of pluralising. Many Europeans (especially Italian and French) hear 'th' and 'sss' or 'th' and 'd' as too close to distinguish easily. This may cause them to blur them into one sound unless specifically urged not too. Blends such as that which occurs at the end of the word 'hundredths' would not be distinguished easily by most non-English background speakers. Remember that English speakers cannot hear all the sounds in other languages either.
To overcome these problems requires firstly their recognition and subsequently exposure, practice, assistance and encouragement.