Use this information to sequence the cards in a vertical stack of fossils in rock strata.
Arrange them from oldest to youngest with the oldest layer on the bottom.
Since this card has a common letter with the first card, it must go on top of the TC card.
The fossils represented by the letters on this card are younger than the T or C fossils on the TC card and indicates fossils in the oldest rock layer. When done you should have a vertical stack of cards with the top card representing the youngest fossils of this rock sequence and the TC card at the bottom of the stack indicating the oldest fossils.
If the letters T and C represent fossils in the oldest rock layer, they are the oldest fossils, or the first fossils formed in the past for this sequence of rock layers.
Now, look for a card that has either a T or C written on it.
If certain fossils are typically found only in a certain rock unit and are found in many places worldwide, they may be useful as index or guide fossils in finding the age of undated strata.
By using this information from rock formations in various parts of the world and correlating the studies, scientists have been able to construct the geologic time scale: This relative time scale divides the vast amount of Earth history into various sections based on geological events (sea encroachments, mountain-building, and depositional events), and notable biological events (appearance, relative abundance, or extinction of certain life forms).We labor under the incorrect notion that students must master basic skills before they can learn higher-order skills or engage in complex activities.Studies in math, reading, and writing clearly demonstrate that the opposite is true.(Means, Chelemer, and Knapp, Teaching Advanced Skills to at Risk Students: Jossey-Bass 1991) Virtually every teacher has acquired some semblance of training in this highly effective method (cooperative learning), estimates are that only about 10 percent of teachers use cooperative learning.One of the simplest forms of cooperative learninghaving students occasionally work in pairs to ensure each others understanding of difficult concepts can be expected to bring immediate effects especially among low-achievers. Teaching about Earths history is a challenge for all teachers.