First we had the problem of this current Gregorian year. Do we call it 2 thousand and ten or twenty-ten? Then the Hebrew calendar throws us one out of leftfield. In long-hand we have no problem. The year 5771 is

Chameishet alafim u’shva mei’ot v’shivim v’echad

However, we get into problems when we try to abbreviate the year assigning the associated Hebrew letters in place of numerical values. For 5771, we use a hey to stand for 5000, the letters having multiple uses as they are simply not enough of them for each value and so 5 stands for 5000. For 700 we have the taf equalling 400 added to the shin, 300. Next we get the ayin for 70 and the alef for 1. All seems okay but try pronouncing them as an acronym. Hatash…. What do we do with the two silent letters at the end?

Read on at http://www.npls.org.uk/Sermons/New/Erev%20Rosh%20Hashanah%205771.html