1 - How tall are you right now? Measure from the start of the paper strip to your height line to find out. 2 - Twice as Tall - Prediction. Double each of the measurements above to predict how tall you would to be if you were twice your height. 3 - Twice as Tall - Actual. Now find out for sure how tall you would be if you were twice your height. Open your paper strip and measure it.