First proofs: engaging math activities for the summer break
Mathematics is certainly not (only) about counting, graphing and solving equations. I do not believe that every child can reach beyond those. I do not believe that a child who does not show an inclination to dig deeper into math mysteries lacks in intellect or creativity. I do think that it is worth trying to find out. I child who gets excited on a discovery of uncommon patterns will have enriched his/her life experiences.
So do try.
Counting heads and tails
What do you need? Three elongated objects I'll call pins, with two distinct ends called, say, a head and a tail.
What is the task? Form a triangle with the three pins and observe the three configurations of heads and tails at the three vertices. Count and record the number of head/head, head/tail, and tail/tail configurations. Repeat the experiment several times and try to make a general observation of what's happening.
What to expect? A child can arrive at several conclusions. For example,
- If there is a head/head vertex there is also a tail/tail vertex, and vice versa.
- There is always a head/tail vertex.
- The three configurations are either all different or all the same, in which case all are head/tail.
Now a proof Make child to argue in support of any of the possible conclusions. For example, how is it possible to prove #2: there is always a head/tail vertex. Here's how I would go about doing that.
Put together any two pins. If their joint is head/tail, we are done. Make it then head/head, say. This leaves two exposed tails to be joined by the the third pin. However this pin is placed, the two new vertices are always tail/tail and head/tail - and we are done in this case also.
Where to go from here? Generalize! See, for example, an older and a more voluble page
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