A man is mowing his lawn when he breaks for lunch he has 23 left after lunch cuts 34 of what is left how much of the whole lawn did he cut after lunch?

I'm going to guess that the figures in your question are percents. After lunch he cuts 34% of the 23% he has left (If I'm reading the question correctly). "Of" usually means to multiply. In this case .34 times .23 equals .0782, or a little under 8%. He cut a little under 8% of the lawn after lunch.