In one to two sentences explain how a thermometer is used and act as a 6th grader

A thermometer is used to measure and show the temperature of things or the surrounding environment by placing it in contact with the object or by using it to measure body temperature, and it helps us determine if something is hot or cold.

rehrase it

A thermometer is a tool that measures temperature by coming into contact with objects or by checking body temperature, and it helps us determine if something is hot or cold. As a 6th grader, we use it to see how hot or cold things are.

A thermometer is used to measure how hot or cold something is, like the temperature of the air or the water. You just stick the end of the thermometer into the thing you want to know the temperature of, and then look at the numbers on the thermometer to find out how hot or cold it is.