Skip to content
Developing Number Sense · Spring Term

Prime Factors, HCF, and LCM

Students will find prime factors, highest common factor (HCF), and lowest common multiple (LCM) of numbers.

Key Questions

  1. Differentiate between prime numbers and composite numbers.
  2. Construct the prime factorisation of a given number.
  3. Explain the practical applications of HCF and LCM in real-world problems.

National Curriculum Attainment Targets

KS3: Mathematics - Number
Year: Year 8
Subject: Mathematics
Unit: Developing Number Sense
Period: Spring Term

About This Topic

The rock cycle describes the continuous transformation of Earth's materials over millions of years. Students learn to distinguish between igneous, sedimentary, and metamorphic rocks based on their formation processes and physical characteristics. They also explore how weathering, erosion, and plate tectonics drive these changes.

This topic is a key part of the Earth Science component of the National Curriculum. It provides context for understanding fossils, the age of the Earth, and natural resources. Students grasp this concept faster through structured discussion and peer explanation, especially when they can simulate the rock cycle using everyday materials to represent geological time.

Active Learning Ideas

Watch Out for These Misconceptions

Common MisconceptionRocks are permanent and never change.

What to Teach Instead

The scale of geological time makes change invisible. Active modeling of the rock cycle helps students visualize that every rock is just at one stage of a very long, circular journey.

Common MisconceptionMetamorphic rocks are made by melting.

What to Teach Instead

Students often confuse metamorphic and igneous processes. Peer teaching can emphasize that metamorphism happens in the solid state due to heat and pressure; if it melts, it becomes magma and eventually igneous rock.

Ready to teach this topic?

Generate a complete, classroom-ready active learning mission in seconds.

Frequently Asked Questions

What are the three main types of rock?
The three main types are igneous (formed from cooled magma or lava), sedimentary (formed from compressed layers of sediment), and metamorphic (formed when existing rocks are changed by heat and pressure).
How are sedimentary rocks formed?
Sedimentary rocks are formed through a process of weathering and erosion, followed by the transport and deposition of sediments. Over millions of years, these layers are compacted and cemented together to form solid rock.
What is the difference between intrusive and extrusive igneous rocks?
Intrusive igneous rocks cool slowly underground and have large crystals (like granite). Extrusive igneous rocks cool quickly on the Earth's surface and have very small crystals or a glassy texture (like basalt or obsidian).
How can active learning help students understand the rock cycle?
Because the rock cycle happens over millions of years, it is too slow to observe. Active simulations (like the Starburst activity) compress this time into a single lesson, allowing students to physically manipulate the 'rock' and see the transitions between states.

Browse curriculum by country

AmericasUSCAMXCLCOBR
Asia & PacificINSGAU