You have to use PEMDAS to solve this equation. P=parenthesis, E=exponents, M=multiply, D=division, A=addition, M=multiplication. As you can see your equation 5+3×16÷3 has no parenthesis, exponents, but it have multiplication so first you have to multiply 3×16 which equals 48 so your left with 5+48÷3 , now as u can see ur equation has division so u have to divide 48÷3 which equals 16, now your left with 5+16, you just have to add 5+16 which equals 21, so your final answer to the question is 21 i hope that helps!!!!!