An E6B is a tool that pilots use to help them figure out things like how long it will take to get somewhere or how much fuel they will need. It looks kind of like a circular slide rule with lots of numbers and scales on it.
Think of it like a special kind of calculator that you use with your hands instead of pushing buttons. Pilots can use it to do all kinds of calculations quickly and easily, like figuring out how fast they're going or how high they're flying.
One side of the E6B has a rotating disk with a special scale on it that measures airspeed. To use it, you twist the disk until the needle lines up with the right numbers for your plane's airspeed and altitude. Then you can use the numbers on the outer ring to figure out how long it will take you to fly a certain distance.
The other side of the E6B has lots of different scales and slide rulers that you can move around to help you figure out things like fuel consumption, wind directions, and altitude changes.
Overall, the E6B is a really handy tool for pilots to have with them when they're flying, and it helps them make sure they're staying on track and flying safely.