In response to Daily Prompt ‘Your days are Numbered‘-What’s the date today ? Write it down, remove all dashes and slashes, and write a post that mentions that number.
Tomorrow Junior has a Math Test in school. Since morning, we (mother and son) have been revising the multiplication tables, working on long-division methods, solving word problems, drawing triangles and squares. We are in a different world today.
My brains is in the hyper-active zone. I am seeing potential math problems in my daily chores – ‘if I eat three almonds everyday, how many almonds have I eaten in the month of May ? Does my spatula have a line of symmetry ?’
So,when I removed the dashes from 11/08/2015 to get 11082015, all I could think of was to quickly do a divisibility test on the number.Here’s a list of divisibility tests Junior and I did for the number. Hope it takes you back to your school days 🙂
11082015 Divisible by 5 Not divisible by 2,4,8 Divisible by 3 and 9 ( 1+1+0+8+2+0+1+5 =18; 18 is divisible by both 3 and 9) Not divisible by 6 ( though the number is divisible by 3, it is not divisible by 2) Divisible by 7 ( double of the last digit(5)=10,1108201-10=1108191; double of the last(1) digit =2, 110819-2 = 110817; double of the last digit=14, 11081 -14 =11067; double of the last digit...Forget it !! pick up the pencil and divide the original number 11082015 by 7. YES!!!YES!!! it is divisible by 7.)Divisibility rule for tricky 7