Reminds me of 7th grade math class, chapter on estimating. Assignment was "Estimate the following values" with problems like 42+28=? or 14*3=?

One of them was 6*7=? Which having memorized my times tables in 4th grade like they told me to, I knew off the top of my head that it's 42. I wrote that. And it was marked wrong because I was too precise.