maths problems

Hi, i would like to create a spreadsheet for my son to use, to test his maths skills. In column A would be the problems, column B his input (the answer) and colum C a simple IF a=b statement. The problem is, ive tried a million different ways, and i cant do column A properly.

I would like the test questions in column A to be randomly generated numbers. so i tried =randbetween(1,10)&"+"&randbetween(1,20) but no luck, as excel doesnt see it as a math problem so column C always shows incorrect. I tried =(randbetween(1,10)+(randbetween(1,20)) but still no luck, it just does the equation and shows the answer in the cell. But i would like it to show 1+4, 10+7 etc....


Can ANYONE help??