Alfonsus ll How do you estimate and round up a percentage

So today I done math for my social dictanceing homelearning and the math. So what I done was that there was two numbers and I had to round them to there nearest tens, when you find your nearest ten you cross out at leat one zero from that number but if there is three numbers you can take out two, when you crossed out your numbers then you have to times tose numbers and you get your answer.