Overview
Years, decades, and centuries are ways to measure time. A year is how long it takes for the Earth to orbit the Sun once. A decade is 10 years. A century is 100 years. Today we’ll build intuition with examples and hands-on activities.
Key Concepts
- Year = 12 months, about 365 days.
- Decade = 10 years. Example: the 2010s means 2010–2019.
- Century = 100 years. Example: the 21st century is 2001–2100.
- There are 10 decades in 100 years, and 100 years in a century.
Simple Explanations
- Year – A single box on a timeline. 1 year apart from the next.
- Decade – A row of 10 consecutive years. Think of a 10-year timeline segment.
- Century – A long stretch of 100 consecutive years. Imagine 10 decades in one century.
Hands-On Activities
- Timeline Art: Draw a long horizontal line. Mark year milestones every 10 years (e.g., 2000, 2010, 2020). Shade every decade block to see how decades fit in a century.
- Compare Centuries: Pick two centuries (e.g., 20th vs 21st). Write down big events from each and place them on a timeline to see how much changes over a century.
- Family Timeline: Create a mini timeline of your family from grandparents to now. Group events by decade to practice recognizing decades.
Practice Questions
- What years are in the 1990s? (1990–1999)
- How many years are in a decade?
- If the year is 2045, what decade is it in?
- What is the 21st century? (2001–2100)
Common Pitfalls
- Thinking 2000s is the 2000–2010 decade; it’s the 2000–2009 decade.
- For centuries, remember there is no year 0; centuries start with year 1.
Helpful Tips
- Use real dates from history to make it concrete.
- Relate to events your child knows (birth year, school years) to anchor the concept.
- Keep sessions short and interactive, then revisit on a timeline later.