A scale model of a building is 8% of actual size. If the model is 1.2 meters tall, how tall is the building?

1.2 m * 0.08 = 0.096 m

You keep your initial meter number and multiply it by 8%. 8% is turned into 0.08 to fit into the problem. I hope this helps! 

You can set up a proportion:

       scale percentage / actual percentage  =  scale size / actual size

             8 % / 100 %   =  1.2 m / unknown m

               8 / 100  =  1.2 / x

Cross-multiply:  8x  =  100·1.2

                          8x  =  120

                             x  =  15 m