New
New
Year 9

Understanding time scales

I can describe key events in the history of Earth and distinguish between billions, millions and thousands of years ago.

New
New
Year 9

Understanding time scales

I can describe key events in the history of Earth and distinguish between billions, millions and thousands of years ago.

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Lesson details

Key learning points

  1. Evidence suggests Earth was formed 4.5 billion years ago.
  2. One billion is one thousand million.
  3. Evidence suggests the first living organisms (microorganisms) appeared around 3.8 billion years ago.
  4. The oldest fossils are around 3.5 billion years old, and the newest fossils are around 10 thousand years old.
  5. Evidence suggests the first land plants appeared 500mya, the first mammals 200mya, and modern humans 350k years ago.

Keywords

  • Billion - One billion is one thousand million (1 000 000 000).

  • Thousand - One thousand (1000) is equal to 10 × 10 × 10.

  • Million - One million is one thousand thousand (1 000 000).

  • Evolution - The characteristics of species gradually change over time, sometimes forming new species. This process is called evolution.

Common misconception

Students struggle to comprehend absolute ages of key events in the history of Earth and evolutionary history.

This lesson provides many examples and context to give students a sense of the differences in time scales involved in the history of Earth and evolution.

Consider completing Task B (Year of Earth) on the playground or along the length of the classroom to give students a more tangible sense of the proportion of time modern humans have been on the planet. Students could be asked to sort the events into order first, then to estimate where they go.
Teacher tip

Content guidance

  • Depiction or discussion of sensitive content

Supervision

Adult supervision recommended

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Lesson video

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6 Questions

Q1.
What name is given to the number 1000?
one hundred
Correct answer: one thousand
one million
one billion
Q2.
Which of the numbers below represents one million?
1000
10 000
100 000
Correct answer: 1 000 000
Q3.
What is the name of the planet upon which we all live?
An image in a quiz
Correct Answer: Earth, the Earth
Q4.
Which picture shows a fossil?
A
B
Correct answer: C
D
Q5.
Which of these things could not become a fossil?
Correct answer: plastic bottle
animal
plant
Q6.
What is a fossil?
a living organism
a rock containing an organism
the remains of a living organism
Correct answer: the mineralised remains of a living organism

6 Questions

Q1.
Write one thousand as a number.
Correct Answer: 1000, 1 000
Q2.
What is the correct way to write one million?
100
1000
Correct answer: 1 000 000
1 000 000 000
Q3.
What name is given to the number 1 000 000 000?
one hundred
one thousand
one million
Correct answer: one billion
Q4.
After studying the ages of rocks, when do scientists think the Earth was formed?
An image in a quiz
hundreds of years ago
thousands of years ago
millions of years ago
Correct answer: billions of years ago
Q5.
Starting with the earliest, put these events in the order they occurred.
1 - cells without a nucleus evolved
2 - multicellular organisms evolved
3 - plants evolved
4 - mammals evolved
Q6.
For how much of the Earth’s history have humans existed?
An image in a quiz
all of it
most of it
half of it
Correct answer: a tiny fraction of it
Q6 © Gorodenkoff/Shutterstock.com