Answer:
4 billion years
Explanation:
Scientists have found the oldest known rocks on Earth. They are 4.28 billion years old, making them 250 million years more ancient than any previously discovered rocks. Earth formed about 4.6 billion years ago from a disk of gas and dust circling the sun.
The Mayan and other Mesoamerican cultures used a vigesimal number system based on base 20 (and, to some extent, base 5), probably originally developed from counting on fingers and toes. The numerals consisted of only three symbols: zero, represented as a shell shape; one, a dot; and five, a bar.
The North Has the most climate variation in the USA. Hope this helps!
The prime meridian is 0 degrees longitude. As you go east from the prime meridian, the longitude increases to 180 degrees. As you go west from the prime meridian longitude increases to 180 degrees.
