abbreviation

[dido4]

We have math on Tue., Thu., Fri., and Sat.

The above sentence,

1.Do we need/have to add a period at the end of the sentence?Why?
->We have math on Tue., Thu., Fri., and Sat..
2.Is the sentence with abbreviations right?

Thank u

[matilda]

there is nothing wrong with using abbreviation, of course. but if this is your everyweek schedule, you'd better say: we have math on sats, tues, ...
(s) is added because you have this schedule every week

[MikeNewYork]

We have math on Tue., Thu., Fri., and Sat.

The above sentence,

1.Do we need/have to add a period at the end of the sentence?Why?
->We have math on Tue., Thu., Fri., and Sat..
2.Is the sentence with abbreviations right?

Thank u

Normally, these abbreviations are followed by a period. This sentence, however, is very informal. Were it formal, it would be better to spell out the days of the week. In a informal letter, it would be understandable with or without the periods.