Derailleur gears operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. For more information about the choice of particular gear ratios and sprocket sizes, see Bicycle gearing. "Derailleur" is a French word, spelled "dérailleur" in French, derived from the derailment of a train from its tracks. Its first recorded use was 1930. At least one notable bicycle industry author has attempted to promote the anglicized spelling of "derailer". As of 2013, however, neither Merriam-Webster nor the Oxford English Dictionary has an entry for "derailer". Various derailleur systems were
Word sort will for most students lead to the abstraction of spelling patterns and the sounds to which they correspond. Word sorts can be teacher directed (closed) or student directed (open). For example, students in the with-in-word pattern phase of word knowledge could sort words according to a vowel pattern; in such sorts there is always a miscellaneous category for words that do not follow the target categories. Game-like formats such as board games and card games can also be effective if they focus on words that reflect spelling patterns. Word-building activities also facilitate abstraction of pattern: word wheels, flip charts, making