Challenge from Westdene Primary, Brighton

9748 /www/nrich/html/content/id/9748/ 5 2013-01-02T09:02:03 <?xml version="1.0" encoding="UTF-8"?> <mdoxml version="1.0">Tom Kimber, a teacher at Westdene Primary School in Brighton emailed us to say: I am a MaST teacher who was lucky enough to be at one of your recent NRICH events in London. I got into a really interesting mathematical discussion with some very advanced pupils in my class about the pattern of the units column in numbers-to-the-power-of. Anyway, after a long and convoluted journey through many different mathematical areas, it has reached a concluding* question. I thought I'd share it with you as my children have ENJOYED getting their teeth into it: Look at this calculation: $7^x + 9^y =$ I get a random number generator to generate two random whole numbers. The first one it generates I place in position $x$. The second number it generates I put at position $y$. What is the probability that, when I complete the calculation $7^x + 9^y =$, I will get a number that is a multiple of $10$ as my answer? Hope you find it as interesting as we are! * - I say concluding... probably not!</mdoxml> 2 3 0 1 1 0 0 Challenge from Westdene Primary, Brighton Pupils at Westdene Primary in Brighton have set themselves a challenge as a result of discussing powers. Site Structural trending Site Structural bbPrimaryTeacher