Mr. Miller Science
An engineer uses science to design things that make our lives easier. Your underwear was designed by an engineer. Really. So were your shoes. Your iPhone. Cars, trucks, buses, bridges, dams, highways, sewers, school buildings, and even the box your Cheerios come in. Pretty much everything we use were all created by engineers using one or more scientific principals and research.
On this website, in the scientific method section, we can see a diagram of the way we all figure things out everyday. You make an observation and then ask a question. Think about it. Propose a solution. Test that solution, then either if it doesn't work, start over, or if it does, communicate it to others. This is the scientific method, and we use it for making our decisions all day, everyday.
Structural engineers design things so that they don't break or fall down. They ensure that their designs have enough strength to withstand outside forces, such as wind and rain, earthquakes, tsunamis, etc. They must also be able to withstand internal forces, such as the books in a library, the cars on a ferry boat. Too many cars, the boat sinks. Bad news.
Civil engineers design bridges, dams, highways, and other large systems and constructions. They need to choose a material, choose a way to build the things, look at what is needed to support and maintain these, and a host of other things.
Chemical engineers design things to either make, store, or use directly from chemicals. Pesticides. Disinfectants. Paint. The paint on a small private airplane weighs about 150 pounds. If they can come up with a paint that weighs less, the airplane will fly better, carry more stuff, and use less fuel.