I was expected to learn decimal equivalents for fractions up to 1/9 (including 2/9 etc.), and I use them now and then.
Instead of working on the higher multiplication tables, why not learn methods of approximation?
Funny that you mention fractions, I started learning them a week ago. Though I can't say I even encountered decimal 1/7 in real life...
This is the public group instrumental rationality diary for July 1-15.
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