I use this worksheet as an inquiry based activity. Students work in pairs to figure out how a double number line can be used to solve percentage problems (ex. what is 40% of 80 or what number is 64 forty percent of?).
Once we have taken up the number line - colour-coded answer sheet provided - the students work through a few questions that allow them to conclude how percents and decimals are linked and how decimals can help us solve percentage problems.