An eight-year old (Grade 3) told me about the "hardest problem" they had to solve on their math test yesterday. Here's the question:
There is a number less than 40, that when divided by 5 leaves a remainder of 3, and when divided by 6 leaves a remainder of 2.
He was very proud to have solved it himself :)
I immediately thought this might be a nice way to introduce him to simple algebra but when we reached home, I realised I couldn't come up with a way to express the problem.
My thoughts were along the lines of:
z = 5x + 3 z = 6y + 2
But then what can you do with
5x + 3 = 6y + 2
except for reaching
y = (5x + 1) / 6
and I have a feeling I'm going down a horribly wrong path.
Is there a "simple" way to solve this problem with algebra?