Question

Addition of rational numbers is commutative.
If true then enter $1$ and if false then enter $0$

Answer 1

True
$a+(b+c)=(a+b)+c$
$\frac{1}{2}+(\frac{2}{5}+\frac{3}{4})=(\frac{1}{2}+\frac{2}{5})+\frac{3}{4}$