Earth is the third planet from the sun and the fifth largest of the planets in this Solar System. The earth is considered to consist of four parts. In the middle of the earth is the inner core. This inner core looks like a ball, surrounded by the rest of the earth. The next layer is called the outer core. This section is 1,380 miles thick and surrounds the inner core. The next layer is called the mantle. The mantle is 1,800 miles thick, solid, and with a density that increases with depth. The outer part of the earth is called the crust. Only 25 miles deep, the crust is where life is sustained.

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Let us now look at the next area of study, which is graphing. Sometimes we use a graph that uses rows and columns. Who knows the difference between a row and a column? Right, the row goes from left to right, and the column from top to bottom. One way to remember this is to think of plants. Plants are grown in rows. The rows of plants are from left to right and in straight lines. Now, do any of you remember old buildings? They have front porches. The things that hold up those porches are called columns. These columns go up and down.

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