DIVISIBILITY BY 7 OF A LARGER NUMBER

I hope you have gone through my last post on "A TRICK TO CHECK DIVISIBILITY BY 7".

If the number is large like 6013 or 564743 having more than three digits, then the method is to apply the trick repeatedly.

Let us check if 6013 is divisible by 7.

• Last digit=3
• Double it; we get 6
• Subtract 6 from 601, the answer is 595
• Is 595 divisible by 7? It is rather difficult to answer.
• So, take the lat digit of 595; that is 5
• Double it; we get 10
• Subtract 10 from 59; the answer is 49
• Is 49 divisible by 7?  Yes!
• So, 595 is divisible by 7 and consequently 6013 is divisible by 7.

GOT IT?

----------------------------------------------------------------------------------------------------------

 If you need online assistance in mathematics (CBSE, IGCSE, PLUS 1 & 2 ETC.) please contact me on raghavanckk@gmail.com    Skype ID: raghavanckk   Mobile: +27(0)737455575

I charge US$5-10 per hour depending on the topic/class.

I have more than 30 years of experience in teaching mathematics at O and A levels in different countries.  At the moment I am also involved with a Mathematics Development Project under  Rhodes University to improve the mathematics efficiency of High School students in South Africa.

I am conversant with the mathematics curricula of many countries.