Maths part 2

• Analogue clock or watch

  Has moving hands, short hand shows the hour, long hand shows the minutes, hours are marked from 1 to 12
• Time on analogue clock or watch

  Include "am" if before noon, "pm" if after noon
• Digital clock or watch


  Shows the time using numbers, time range is 24 hours
• Time on analogue and digital clocks

  • 6:40 am (analogue) or 06:40 (digital)
  • 6:40 pm (analogue) or 18:40 (digital)
• Calendar


  Based on the time it takes the Earth to go around the Sun - 365.2425 days, add a day to February every four years to compensate
• Time conversions


  1. 60 seconds = 1 minute

  2. 60 minutes = 1 hour

  3. 24 hours = 1 day

  4. 7 days = 1 week

  5. 1 year = 365 days

  6. 1 leap year = 366 days
• It takes the Earth 365.2425 days to go around the Sun
• Analogue clock or watch

  Has moving hands, short hand shows the hour, long hand shows the minutes, hours are masked from 1 to 12
• Converting 365.2425 days to weeks, days, hours, minutes and seconds

  1. 365 days

  2. 0.2425 days

  3. 52 weeks, 1 day, 5 hours, 49 minutes, 12 seconds
• Time read from an analogue clock or watch

  Include "am" if before noon, "pm" if after noon
• Thandal and Petunia recharged their cellphone batteries simultaneously


  Thandal could use his cellphone for 9 days, 13 hours and 8 minutes, Petunia could use her cellphone for 7 days, 17 hours and 15 minutes
• Digital clock or watch


  Shows the time using numbers, time range is 24 hours
• Thandal could use his cellphone for longer than Petunia
• Calculating how much longer Thandal could use his cellphone than Petunia

  2 days, 19 hours, 53 minutes
• Time examples


  • 6:40 am (analogue) or 06:40 (digital)
  • 6:40 pm (analogue) or 18:40 (digital)
• Calendar


  Based on the time it takes the Earth to go around the Sun - 365.2425 days, add a day to February every four years to compensate
• Time conversions


  1. 60 seconds = 1 minute

  2. 60 minutes = 1 hour

  3. 24 hours = 1 day

  4. 7 days = 1 week

  5. 365 days = 1 year

  6. 366 days = 1 leap year
• It takes the Earth 365.2425 days to go around the Sun
• Converting 365.2425 days to weeks, days, hours, minutes and seconds


  1. 365 days + 0.2425 days

  2. 52 weeks, 1 day + 5.82 hours

  3. 52 weeks, 1 day, 5 hours + 49.2 minutes

  4. 52 weeks, 1 day, 5 hours, 49 minutes, 12 seconds
• Thandai and Petunia cellphone battery usage

  1. Thandai - 9 days, 13 hours, 8 minutes

  2. Petunia - 7 days, 17 hours, 15 minutes

  3. Thandai could use his cellphone 1 day, 19 hours, 53 minutes longer
• There are 60 seconds in a minute and 60 minutes in an hour
• Converting seconds to hours and minutes

  1. Divide seconds by 3600 for hours. 2. Convert hours to decimal hours. 3. Convert decimal hours to minutes and seconds.
• Converting hours to decimal hours

  Multiply decimal part by 60 to get minutes
• Converting seconds to hours

  1 second = 1/3600 hours
• Converting decimal hours to minutes and seconds

  1. Multiply decimal part by 60. 2. Calculate remaining seconds.
• 60 seconds ≈


  1 minute
• 3600 seconds ≈


  1 hour
• 900 seconds ≈


  15 minutes
• 1800 seconds ≈


  30 minutes
• 1200 seconds ≈


  20 minutes
• 0.5 hours ≈


  30 minutes
• 0.75 hours ≈


  45 minutes
• 0.75 hours ≈


  45 minutes
• A.M.


  Before 12:00 noon
• P.M.


  After 12:00 noon
• 
  

  Calculating distance,speed and time
• Distance


  Measure of how far an object travels
• Speed


  Rate at which an object covers distance; usually measured in units like m/s or km/h
• Time


  Duration it takes for an object to cover a certain distance; measured in units like s, min, or h
• Speed × Time = Distance


  Equation showing the relationship between distance, speed, and time