What is a math fact?

Question

What is a fact in a fact family, what is a basic fact, a math fact, and a doubles fact. Can't find an explicit definition online.

Answer 1

None of these terms has mathematical meaning. I'm not surprised that you can't find definitions.

Since you ask about a "doubles fact" I will guess that your question comes from some context that involves early elementary school arithmetic. There kids often learn "the doubles": $2+2=4$, $3+3=6$ and so on, to help them with number sense and mental arithmetic. These might be the doubles facts you refer to.

The multiplication table might be called "math facts". So might the equivalence of the expressions like $$ 2 + 3 = 5 $$ and $$ 5-3 = 2 $$ that connects addition and subtraction.

The collection of all such strategies might be called "math facts" or "basic facts".

Note: this is not vocabulary I like. But it is out there in schools where teachers are doing a good job. Learning arithmetic this way is more interesting than mastering algorithms.

Answer 2

According to some points of view, a fact can be equated with a true proposition.

If so, a mathematical fact is a mathematical true proposition, i.e. a mathematical theorem.