Each week Another parent and I work with 4th – 6th grade students and Math Olympiad problems. This week they had a test.
The most challenging problem involved finding the ones digit of a number with 50 factors of 7. Students were expected to see a pattern:
7 x 7 = 49
7 x 7 x 7 = ??3
7 x 7 x 7 x 7 = ???1
7 x 7 x 7 x 7 x 7 = ???7
7 x 7 x 7 x 7 x 7 x 7 = ????9
The ones digit pattern= 9,3,1,7,9,3,1,7,9…
I don’t think anyone figured it out.
