ch 34 calender and time

1. Ch - 34
calender

2. Calender :
a chart or series of pages showing the days,
weeks, and months of a particular year, or
giving particular seasonal information.

3. Year : the time taken by the earth to make
one revolution around the sun.
.
the period of 365 days (or 366 days in
leap years) starting from the first of
January, used for reckoning time in
ordinary circumstances.

4. Month :
each of the twelve named periods into which a year is divided.
There are twelve months in a year .

5. Days of week :
There are days in a week . they are
Sunday , monday , tuesday ,
Wednesday , thursday , friday, saturday .

6. Hours in a day :
There are 24 hours in a day .
24 hours = 1 day

7. Minutes in a day :
1 = 1440
2 = 2880
3 = 4830

9. Remenber :

10. UNITS OF TIME :
The smallest units of time are seconds
The larger units of time are :
days, weeks, months and years

11. Let us look at the relations
between these units :

20. PRACTICE QUESTIONS :

21. ANSWERS :
1. a) 240 Seconds
b) 900 Seconds
c) 455 Seconds
d) 163 Seconds
1. a) 300 Minutes
b) 132 Minutes
c) 465 Minutes
d) 609 Minutes

30. PRACTICE QUESTIONS :

31. ANSWERS :
1. a) 1:35 a.m
b) 10:30 p.m
c) 3:50 p.m
d) 10:00 a.m
1. a) 1930 hours
b) 0405 hours
c) 2100 hours
d) 0000 hours

32. Contents
❖ Calendar : weeks , months and years
❖ Conversion of days,weeks ,
months and year
❖ Writing days in short form

35. A Year has 12 Months .
There are 365 days in a year.
There are 52 weeks in a year .
A Month has 4 weeks .
A Week has 7 days. .
Number of months, weeks & days

36. We use Knuckles to find the number of days in each month

37. Knuckles have 31 days and Spaces have 30 days.
Number of days in each month

42. Look at the calendar of the current year and answer
the following questions.
a) Which months have 31 days?
b) How many wednesdays are there in January ?
c) Does February have 29 days in 2021 ?
d) Which is the last day of the year ?
e) Find the months in which there are 5 Sundays.
f) How many years make a century ?

43. A leap year has 366 days
In an ordinary year, if you were to count all the days in a
calendar from January to December, you’d count 365 days. But
once in every four years, February has 29 days instead of 28. So,
there are 366 days in the year. 2020 was a leap year.

46. How to check a year leap year or not ?
The last two digits of a leap year are
divisible by 4 .
Eg : 2008 , 2012, 2016 ,2020 are leap years.

47. Which of the following years are leap years?
a)2001
b)2024
c)2006
d)2021
e)1848

48. Conversion of years into days
To convert years into days
we multiply by 365.
1 year = 365 days

49. Conversion of years into days
Example 1:
Convert 1 year 12 days into days.
I year = 365 days
1 year 12 days = 1 x 365 days + 12 days
= 365 days +12 days = 377 days

50. Example 2:
Convert 3 years 49 days into days.
1 year = 365 days
3 years 49 days = 3 x 365 days + 49 days
= 1095 days + 49 days
= 1144 days

51. Practice questions
Convert the following into days.
a) 4 years
b) 10 years 50 days
c) 6 years 75 days
d) 9 years 9 days

52. Conversion of weeks into days
To convert weeks into days
we multiply by 7.
1 week = 7 days

53. Conversion of weeks into days
Example 1:
Convert 6 weeks into days.
I week = 7 days
6 weeks = 6 x 7 days
= 42 days

54. Conversion of weeks into days
Example 2 :
Convert 3 weeks 4 days into days.
I week = 7 days
3 weeks 4 days = 3 x 7 days + 4 days
= 21 days + 4 days = 25 days

55. Conversion of months into days
To convert months into days
we multiply by 30.
1 month = 30 days

56. Example 1:
Convert 3 months into days.
I month = 30 days
3 months = 3 x 30 days
= 90 days

57. Example 2:
Convert 4 months 10 days into days.
I month = 30 days
4 months 10 days = 4 x 30 days + 10 days
= 120 days + 10 days = 130 days

58. Practice questions
Convert the following into days.
a) 10 weeks
b) 5 weeks 4 days
c) 6 months 12 days
d) 9 months 15 days

59. Conversion of years into months
To convert years into months we
multiply by 12.
1 year = 12 months

60. Convert the following into months
Example 1:
5 years
1 year = 12 months
5 Years = 5 x 12 months = = 60 months

61. 10 years 2 months into months
= 10 x12 months + 2 months
= 120 months + 2 months
= 122 months
Practice Ex 10.6

62. Practice questions
Convert the following into months.
a) 7 years
b) 4 years 5 months
c) 2 years 11 months
d) 9 years 9 months

63. Writing Dates in Short Form
14 January 2021
(Day ) (Month ) (Year )
Short form: 14/01/2021 or 14.01.2021

64. Write the following dates in short form .
a)15 th April 2015
b) 1 st September 1778
c) 2 nd November 2020
d)29 th June 2010

65. If a boy was born on 29
February 2004, how many
real birthdays did he have
before 2021?