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State Board · Class 5 · Environmental Studies

Lesson 2: History and the Concept of 'Time'

5 concepts · 40 practice questions with answers · Free to read

This lesson is also in: मराठी

Division of time and the timeline

From daily life

A school day has a timetable: periods, a break, and a bell. History also needs a timetable of its own, so that we can say which event came first and how long ago it was.

Simple definition

A century (शतक) is 100 years and a millennium (सहस्रक) is 1000 years. Arranging years one after another on a line is the timeline (कालरेषा), or unilinear division of time.

Rule 1: Small units of time — The earth rotates once in 24 hours, with about 12 hours of day and 12 of night. 7 days make a week, 2 weeks a fortnight, 4 weeks a month and 12 months a year.

  • Easy : Easy: 3 weeks = 21 days.
  • Medium : Medium: 2 years = 24 months.
  • Exam-type : Exam: A fortnight is 14 days, so 3 fortnights are 42 days.

Rule 2: Centuries on the timeline — The 16th century is the years 1501 to 1600. To find the century of a year, look at the hundreds: 1757 is in the 18th century, 1857 in the 19th and 1947 in the 20th. A year that ends in 00, like 1900, belongs to the century that is ending.

Number lineNumber line from 1400 to 1800 in steps of 100. Shaded from 1500 (open) to 1600 (closed). Point S at 1523.14001500160017001800Sshaded: one century

In the figure : In the figure the shaded part (1501–1600) is the 16th century, and the point S at 1523 lies inside it.

  • Easy : Easy: 1757 is in the 18th century.
  • Medium : Medium: 1900 belongs to the 19th century.
  • Exam-type : Exam: 2001 is the first year of the 21st century.

Rule 3: How long between two years — Subtract the earlier year from the later year. From 1820 to 1890 is 1890 − 1820 = 70 years. From 1857 to 1947 is 90 years.

Number lineNumber line from 1800 to 1900 in steps of 10. A jump from 1820 to 1890 labelled +70 years. Point A at 1820. Point B at 1890.180018201840186018801900AB+70 years

In the figure : In the figure the arrow from 1820 to 1890 is 1890 − 1820 = 70 years long.

  • Easy : Easy: 1950 − 1920 = 30 years.
  • Medium : Medium: 1947 − 1857 = 90 years.
  • Exam-type : Exam: In 2026, 1947 was 2026 − 1947 = 79 years ago.
Remember

Century = 100 years, millennium = 1000 years. Later year − earlier year = gap.

Common mistake

Calling 1857 the 18th century. 1857 is in the 19th century (1801–1900).

Shortcut

Memory clue: "शेकडा + 1 = शतक", म्हणजे 1857 → 18 + 1 = 19 वे.

Spot the difference

UnitLength
Fortnight2 weeks
Century100 years
Millennium1000 years

Practice questions

Easy
  1. 1How many days make a fortnight?
  2. 2How many years make a century?
  3. 3How many years make a millennium?
Medium
  1. 4Which century is 1857 in?
  2. 5Which years make up the 16th century?
  3. 6How many years from 1820 to 1890?
Challenging
  1. 7How many years between 1857 and 1947?
  2. 8Which century does the year 2000 belong to? Why?
Show answers (try them yourself first)
  1. 114.
  2. 2100.
  3. 31000.
  4. 4The 19th century.
  5. 51501 to 1600.
  6. 670.
  7. 790.
  8. 8The 20th century, because the 20th century is 1901 to 2000.

The Common Era

From daily life

If your uncle says "I was born in 1990" and your grandmother says "the temple was built in 300 BCE", how do you compare the two dates? We need one common calendar and a rule for going backward.

Simple definition

CE (इ.स., Common Era, also AD) counts years forward from a starting point. BCE (इ.स.पू., Before Common Era, also BC) counts years backward before it.

Rule 1: CE and BCE — AD (Anno Domini) began in memory of Jesus Christ, and the calendar we use is based on it. The first century CE is 1–100 CE, and the first millennium CE is 1–1000 CE. Years before it run in reverse order: the first century BCE is 100–1 BCE. Mahavir (599–527 BC) and Buddha (563–483 BC) are examples of BCE dates.

  • Easy : Easy: 1947 CE is after 300 BCE.
  • Medium : Medium: The second century CE is 101–200 CE.
  • Exam-type : Exam: The first century BCE is 100–1 BCE, counted backward.

Rule 2: Which comes first? — In BCE, a bigger number is earlier in time. So 350 BCE is before 150 BCE. Between two marks on a BCE line, read the years on both sides and check which way the numbers go. An event in BCE always comes before any event in CE. There is no year 0 between the two eras: 1 BCE is followed by 1 CE.

Timeline (BCE and CE)Timeline from 400 BCE to 100 BCE, with a mark every 100 years. Event X in 350 BCE. Event Y in 150 BCE.400 BCE300 BCE200 BCE100 BCEXY

In the figure : In the figure X is at 350 BCE and Y is at 150 BCE, so X happened first. Between two marks, read the years on both sides and check which way the numbers go.

Timeline (BCE and CE)Timeline from 200 BCE to 200 CE, with a mark every 200 years; the line passes from BCE to CE and there is no year 0. Event U in 50 BCE. Event V in 50 CE.200 BCE200 CEBCECEUV

In the figure : In the figure U (50 BCE) is on the left of the dashed line and V (50 CE) is on the right, so U happened before V. There is no year 0 between the two eras.

  • Easy : Easy: 500 BCE is earlier than 400 BCE.
  • Medium : Medium: 20 BCE is earlier than 20 CE.
  • Exam-type : Exam: Order 100 CE, 100 BCE, 300 BCE: 300 BCE, 100 BCE, 100 CE.

Rule 3: Centuries and gaps in BCE — The 2nd century BCE is 200–101 BCE and the 1st century BCE is 100–1 BCE; the 2nd comes first because it is further back. The 3rd century BCE is 300–201 BCE. To find a gap, subtract the smaller from the larger: from 320 BCE to 185 BCE is 320 − 185 = 135 years.

Timeline (BCE and CE)Timeline from 300 BCE to 1 BCE, with a mark every 100 years. Shaded from 200 BCE to 101 BCE (both years included). Shaded from 100 BCE to 1 BCE (both years included).300 BCE200 BCE100 BCE2nd century BCE1st century BCE

In the figure : In the figure the first shaded stretch (200 BCE to 101 BCE) is the 2nd century BCE and the second (100 BCE to 1 BCE) is the 1st century BCE. The 2nd century BCE comes first, because it is further back in time.

Timeline (BCE and CE)Timeline from 300 BCE to 100 BCE, with a mark every 50 years. An arrow from 250 BCE to 110 BCE labelled 140 years. Event M in 250 BCE. Event N in 110 BCE.300 BCE200 BCE100 BCEMN140 years

In the figure : In the figure the arrow from 250 BCE to 110 BCE is 250 − 110 = 140 years long.

Live figure

The Common Era

In the app you can move this figure with your finger.

Open in the app
  • Easy : Easy: 300 BCE is in the 3rd century BCE (300–201).
  • Medium : Medium: 320 BCE − 185 BCE = 135 years.
  • Exam-type : Exam: Buddha was born in 563 BCE (6th century BCE) and died in 483 BCE (5th century BCE).
Remember

CE counts forward, BCE counts backward. Bigger BCE number = earlier. No year 0.

Common mistake

Thinking 100 BCE is later than 300 BCE. Counting backward, 300 BCE is earlier.

Shortcut

Memory clue: "इ.स.पू. मध्ये संख्या कमी होते = काळ पुढे जातो".

Spot the difference

EraCountingExample order
BCEBackward300, 200, 100 BCE
CEForward100, 200, 300 CE
BetweenNo year 01 BCE → 1 CE

Practice questions

Easy
  1. 1What does CE stand for?
  2. 2What does BCE stand for?
  3. 3Which is earlier: 350 BCE or 150 BCE?
Medium
  1. 4Which is earlier: 50 BCE or 50 CE?
  2. 5Which years make up the 2nd century BCE?
  3. 6Which comes first: the 2nd or the 1st century BCE?
Challenging
  1. 7How many years from 250 BCE to 110 BCE?
  2. 8Mahavir lived 599–527 BCE. Which century BCE was that, and for how many years did he live?
Show answers (try them yourself first)
  1. 1Common Era.
  2. 2Before Common Era.
  3. 3350 BCE.
  4. 450 BCE.
  5. 5200 BCE to 101 BCE.
  6. 6The 2nd century BCE.
  7. 7250 − 110 = 140.
  8. 8The 6th century BCE; 599 − 527 = 72 years.

Measuring time and different eras

From daily life

On a letter you write the date: day, month and year. In history, different peoples began counting years from different big events. These counting systems are called eras.

Simple definition

An era (कालगणना) counts years from a special event. Units of time are second, minute, hour, day, week, fortnight, month, year, century and millennium.

Rule 1: Eras and the events they remember — Rajyabhishek Shaka: Chhatrapati Shivaji Maharaj's coronation, 1674 AD. Shalivahan Shaka and Vikram Samvat: used in India. Hijri Era: the migration of Prophet Muhammad. Shahenshahi Era: used by the Parsis.

  • Easy : Easy: Rajyabhishek Shaka began in 1674 AD.
  • Medium : Medium: The Hijri Era remembers the migration of the Prophet.
  • Exam-type : Exam: The Shahenshahi Era is used by the Parsis.

Rule 2: Context and conversion — Shivaji Maharaj escaped from Agra in 1666 and was crowned in 1674; he died in 1680. To change a Shalivahan Shaka year to CE, add 78: Shaka 1596 is 1596 + 78 = 1674 CE. For Vikram Samvat subtract 57: VS 1731 is 1731 − 57 = 1674 CE.

  • Easy : Easy: Shaka 1596 + 78 = 1674 CE.
  • Medium : Medium: Vikram Samvat 2083 − 57 = 2026 CE.
  • Exam-type : Exam: Shaka 1948 + 78 = 2026 CE.
Remember

Era = counting from a big event. Shaka + 78 = CE; Vikram Samvat − 57 = CE.

Common mistake

Subtracting 78 from a Shaka year. Add 78 to reach CE.

Shortcut

Memory clue: "शक + 78 = इ.स.".

Spot the difference

EraRemembers
Rajyabhishek ShakaShivaji's coronation, 1674 CE
Shalivahan ShakaCE = Shaka + 78
Vikram SamvatCE = VS − 57
HijriMigration of the Prophet

Practice questions

Easy
  1. 1Name the units of time from smallest to largest in the lesson.
  2. 2What are the three parts of a date?
  3. 3Which era remembers Shivaji Maharaj's coronation?
Medium
  1. 4In which year was Shivaji Maharaj crowned?
  2. 5Which era do the Parsis use?
  3. 6Change Shaka 1948 to CE.
Challenging
  1. 7Change Vikram Samvat 2083 to CE.
  2. 8Shivaji Maharaj was crowned in 1674 and died in 1680. For how many years did he rule as a crowned king?
Show answers (try them yourself first)
  1. 1Second, minute, hour, day, week, fortnight, month, year, century, millennium.
  2. 2Day, month and year.
  3. 3Rajyabhishek Shaka.
  4. 41674 CE.
  5. 5Shahenshahi Era.
  6. 61948 + 78 = 2026 CE.
  7. 72083 − 57 = 2026 CE.
  8. 81680 − 1674 = 6 years.

Historical periods

From daily life

If the whole life of the earth were a very long film, the part that humans have written about would be only the last few seconds. Before that, there were no letters or books.

Simple definition

The solar system formed about 4.5 billion years ago. History is divided into two periods: prehistoric (प्रागैतिहासिक, no written records) and historic (ऐतिहासिक, written records available).

Rule 1: Two periods — The prehistoric period has no written records, so we learn about it from tools, bones and paintings. The historic period has written records such as inscriptions and books. Writing began only about 5000 years ago, so the historic period is a very short part of the earth's 4.5 billion years.

  • Easy : Easy: Stone Age tools belong to the prehistoric period.
  • Medium : Medium: An inscription belongs to the historic period.
  • Exam-type : Exam: 4.5 billion years is 4500 million years, but writing is only about 5000 years old.
Remember

Prehistoric = no written records; historic = written records.

Common mistake

Thinking prehistoric means no people. People lived then, but left no writing.

Shortcut

Memory clue: "लिखित नोंद नाही = प्राग, आहे = ऐतिहासिक".

Spot the difference

PeriodWritten recordsLearn from
PrehistoricNoneTools, bones, paintings
HistoricYesInscriptions, books

Practice questions

Easy
  1. 1How old is the solar system?
  2. 2Name the two periods of history.
  3. 3Which period has written records?
Medium
  1. 4How do we learn about the prehistoric period?
  2. 5Is a Stone Age tool a sign of the prehistoric or historic period?
  3. 6Did people live in the prehistoric period?
Challenging
  1. 7Writing began about 5000 years ago. How many times older is the solar system? Roughly.
  2. 8Why is the historic period a tiny part of the earth's age?
Show answers (try them yourself first)
  1. 1About 4.5 billion years.
  2. 2Prehistoric and historic.
  3. 3The historic period.
  4. 4From tools, bones and paintings.
  5. 5Prehistoric.
  6. 6Yes, but they left no writing.
  7. 74,500,000,000 ÷ 5000 = 900,000 times.
  8. 8Writing began only about 5000 years ago, but the earth is 4.5 billion years old.

Dating methods

From daily life

A doctor guesses a child's age from the teeth, and a forester counts rings on a cut tree. Scientists have similar methods to find the age of old things.

Simple definition

Dating methods (कालनिश्चिती पद्धती) estimate the age of soil layers and remains. Two are Carbon-14 analysis and tree-ring analysis (dendrochronology).

Rule 1: Carbon-14 — Willard Libby invented the Carbon-14 method, and it can date objects up to about 60,000 years old. A living thing takes in C-14, but after death the C-14 in it slowly decreases. Measuring what remains gives its age. About every 5730 years the amount becomes half.

  • Easy : Easy: C-14 decreases after death.
  • Medium : Medium: After 5730 years, half the C-14 is left.
  • Exam-type : Exam: After 2 × 5730 = 11,460 years, one-fourth is left.

Rule 2: Tree rings and a worked example — A tree adds one ring each year, so counting the rings of a cut tree tells its age: 120 rings means about 120 years. A pot found to be 5000 years old was made about 5000 − 2026 = 2974 years before the Common Era began, so about 3000 BCE.

  • Easy : Easy: One ring = one year.
  • Medium : Medium: 85 rings means about 85 years.
  • Exam-type : Exam: A 5000-year-old pot dates to about 3000 BCE (5000 − 2026 ≈ 2974).
Remember

C-14 for dead organisms up to about 60,000 years; tree rings count years.

Common mistake

Using C-14 on a stone. It works only for things that were once alive.

Shortcut

Memory clue: "वलय = वर्ष, C-14 = निम्मे होते".

Spot the difference

MethodUsed for
Carbon-14Dead organisms (bones, wood) up to about 60,000 years
Tree ringsAge of trees and their wood

Practice questions

Easy
  1. 1Name two dating methods.
  2. 2Who invented the Carbon-14 method?
  3. 3What happens to C-14 after an organism dies?
Medium
  1. 4Up to how many years can C-14 date objects?
  2. 5How many rings does a 60-year-old tree have?
  3. 6After about 5730 years, how much C-14 is left?
Challenging
  1. 7After about 11,460 years, how much C-14 is left?
  2. 8A pot is found to be 5000 years old. About which BCE year was it made?
Show answers (try them yourself first)
  1. 1Carbon-14 analysis and tree-ring analysis.
  2. 2Willard Libby.
  3. 3It slowly decreases.
  4. 4About 60,000 years.
  5. 5About 60.
  6. 6Half.
  7. 7One-fourth (half of half).
  8. 8About 5000 − 2026 ≈ 2974, so about 3000 BCE.

Quick revision

  • Century 100 years; millennium 1000 years; CE counts forward, BCE backward.
  • Prehistoric = no written records; historic = written records.
  • Dating: Carbon-14 and tree rings.