The only difference between the control group and the test group were two lessons, a total of 50 minutes spent teaching not math but a single idea: that the brain is a muscle. Giving it a harder workout makes you smarter. That alone improved their math scores.
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Can I really leave this up to him, at his age?
I�m still an anxious parent. This morning, I tested him on the way to school: �What happens to your brain, again, when it gets to think about something hard?�
�It gets bigger, like a muscle,� he responded, having aced this one before.
