  Centrale des maths - centraledesmaths.uregina.ca  Dilemmes & doutes    « D & D »    Sujet: divisibility by 3   nouvelle recherche

7 articles trouvés pour ce sujet.    Page1/1            Divisibility by 3 2018-11-20 Ray pose la question :There is a rule that a number is divisible by 3 if the sum of its digits are divisible by 3 (for example, 81=8+1=9 {divisible by 3} and 33=3+3=6 {again, divisible by 3}) I know this works but I don't know why! Please help.Penny Nom lui répond.     Some 6 digit numbers 2012-10-23 Mason pose la question :How many different 6 digit numbers can you make using the digits 1 ,2 5, 6, 7, and 9? How many of these six-digit numbers are divisible by 6?Penny Nom lui répond.     Powers 2010-10-20 dylan pose la question :how do you write 20736 in exponential form .same for 1728 and 50625. is there a formula to figure out how to express large know numbers in exponential form.Penny Nom lui répond.     Divisibility by 3 2010-05-23 Cathleen pose la question :To math central. I have to do a maths extension question that I don't understand. At first I thought I did. It is about the dividing by three. In one part of the question, it asks me to show that the rule of division by three does not work for 23142 with a little 5 down the bottom. What doe base 5 mean? We first thought that the little 5 down the bottom meant multiplying y the power of five. Can you please tell me what it means so I can finish this question?Penny Nom lui répond.     The sum of the digits of a number 2008-06-23 Ben pose la question :Question: Using mathematical induction, prove that if the sum of the digits of a number is divisible by three, then the number itself is also divisible by 3.Penny Nom lui répond.     Divisibility rules 2001-09-07 A student pose la question :Why is it that when you add the digits of a number you can tell what the multiples of that number are. Example: 12131313111, 1+2+1+2+1+3+1+1+1=18, therefore 12131313111 is divisble by 2, 9, 18, & 3 because those numbers are divisble by 18. Penny Nom lui répond.     Divisibility by 3 2000-03-24 Pat Walsh pose la question :W hy does it work when you add the digits of a number then divid by three to see if the number is divisible by threePenny Nom lui répond.      Page1/1    Centrale des maths reçoit une aide financière de l’Université de Regina et de The Pacific Institute for the Mathematical Sciences.    Qui sommes-nous :: carte du site :: our english site