Why Are Telephone Numbers XXX-XXX-XXXX and why not XXXXXXXXXX?

Ever wonder why telephone numbers are 3 numbers then 3 more numbers then 4 numbers?

I am not talking about why from a process standpoint.  Although it is good to know that the first three numbers are the Area Code, the second three are the City Code, and the last four are the Line Number, I am talking about why is it 3-digits then 3-digits and then 4-digits?

I am asking why not just 10 digits all together?

Well have you ever tried to remember ten things given to you at one time?  

Our brains are really complex and amazing, but when things are typically given to us in groups larger than 5 most people start to struggle to remember them.  Remembering ten things at once is really a skill few people possess. The working verbal or visual memory is what is used to remember information.  When information is grouped into smaller chunks it allows our working memory to remember/recall the numbers much easier.

There are many online resources that offer to test your memory through tests known as Digit Span or Memory Span tests.  Currently I can remember around 7 things, 8 is hard.  Trying to remember them and then recall them backwards is even more challenging! So, to keep things simple telephone numbers are 3-digits, 3-digits, and 4-digits.  

This allows most people to remember telephone numbers, although today's mobile phones make this much easier!

Students Struggling with Facts:

Students who struggle in math typically will struggle with being able to remember 3 or 4 digit blocks of numbers. If you have a student who is struggling in math try giving a digit span test and see how they do.  If they struggle getting to 5 digits and are 6 years old or older, then they will probably have difficulty memorizing facts or doing word problems with multiple pieces of information.

I'd encourage you to work with them on their visual and verbal memory skills and see if that helps to improve their mathematics abilities! - Dan    

MasterPieces2 with gold border

MasterPieces help students with memory issues to process information without needing to hold all of the information in their short term memory.

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