How I plan - planning a mini unit on the history of telling the time

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I have been asked many times by so many people how do I plan for home educating 6 children - the truthful answer is "minimally"!

We do short units based on a topic either that one of the children has shown an interest in or that I have chosen because I feel like a skill of some kind is needed.

This time I noticed that my younger children while great at reading the time on a digital clock were getting confused by actual clock faces - so the idea for a mini telling the time unit was born.  

When I started looking into it I realized that repeatedly answering "what is the time? " questions would be boring so I paired it with a little history of timekeeping to give us more opportunities for activities.

I normally plan for either 5 - 10 days of activities based on a topic this stops people getting bored and means that it doesn't feel overwhelming to plan or implement. We still do lots of other things during the day maths and reading I do individually with each child and my oldest is now studying for GCSEs. Plus we love doing seasonal activities and craft - all this means I am not going to be spending hours a day on the topic we are doing.

I should add here - I plan for 5-10 days BUT this doesn't mean that I insist on doing this one day after the next. We might wake up one day and decide to go out for the day instead - or maybe we just don't feel like doing it that day - that's fine. Realistically this next unit could take 5 days or it could take 20 days. It depends what life throws at us!.

The only things I bought for this unit were;

Self inking clock face stamp

and the teachers pay teachers item phases of the moon playdoh mats (linked below)

 

The lessons

 

Day 1



Introduce the idea of the lunar cycle as a timekeeping tool.


Early hunter gatherers made marks on stick and bone to track the phases of the moon. This was the very earliest attempt at a calendar around 20,000 years ago.


Activity 1 - Phases of the moon playdoh mat (Teachers pay teachers)


Activity 2 - Introduce telling the time practice with the clock stamp whole hours time (i.e 1pm, 2pm, etc).





Day 2 


Recap questions 


What is a lunar cycle?


How did early people try to use the lunar cycles to create a calendar?


The Egyptian calendar


The early Egyptians used lunar months to track their year. They had 3 seasons called flood, seed and harvest which each last 4 lunar months. 


There is a major problem with using lunar cycles to create a calendar - the movement of the moon around the Earth (which takes 28 or 29 days) just doesn't match up with the movement of the Earth around the sun (which takes 365 and a quarter days). This makes calendars based on lunar cycles difficult to keep track of. 


Later Egyptians (around 3000BCE) realised that the star Sirius rose next to the sun once every 365 days - they used this fact to create a new calendar of 12 months with 30 days each. They then added 5 extra days (to make it up to the 365 days) at the end of the year. According to Egyptian myth the god Thoth won these extra days in a game of dice against the moon!.


Activity 1 (for older children) - Extra reading 


Ancient-egypt online



Activity 1 (younger children) Months of the year cut and paste ordering activity (Teachers pay teachers freebie)



Activity 2 - Practice telling the time using clock stamps 



Day 3  - 


Recap questions


What is a lunar cycle?


How did early people try to use the lunar cycles to create a calendar?


What is the problem with using the lunar cycle to create a calendar?


How did the Egyptians change their calendar over time?


The Roman Calendar


The founders of Rome created a 10 month calendar that had 6 months of 30 days and 4 months of 31 days. This gave a total year length of 304 days - too short!


The second ruler of Rome  (Numa Pompilius) tried to improve on this and added January and February the the END of the year as well as changing the lengths of the months so that now half had 29 days and half had 30 days This made the year 355 days long which was closer but still too short. 


Later Romans added a new month which only happened every other year - this started to get extremely confusing but things stayed that way until Julius Caesar came along!.


In 46BCE Julius caesar declared that the current year would last 445 days instead of 355, he moved January and february to the start of the year and decided that the months would be either 30 or 31 days long apart from February which would be 29 days or 30 days every 4 years. 


This new calendar was called the Julian calendar and it was much closer to being the correct length BUT was 11 minutes 14 seconds too long. Nevertheless the senate took one of the months Quintilis and renamed it JULY in honour of julius caesar.


Later on the senate also renamed the month of Sextilis calling it August in honour of a later emperor (Augustus Caesar).They also stole a day from february and made August 1 day longer!


By the 1580s all those extra 11 minutes and 14 seconds had added up and it was becoming problematic. Pope Gregory XIII decided he needed to get things back on track so he came up with a plan. He declared that that year they would skip some of October going straight from the 4th to the 15th . He also Changed the leap years so that leap years would still happen BUT every year which was divisible by 100 (for example 2100 would not be a leap year) These changes took care of the extra time.


This is called the Gregorian calendar and is the calendar we still use today.


Activity 1 - See how ours shadows change during the day (first grade round up)


Activity 2 - practice telling the time with our clock stamp

Day 4 

Recap questions


What is a lunar cycle?


How did early people try to use the lunar cycles to create a calendar?


What is the problem with using the lunar cycle to create a calendar?


How did the Egyptians change their calendar over time?


How did the month of July get its name?


How did the month of August get its name?


What is the name of the calendar we use today?


Hours


The Egyptians were happy with how they tracked the year but what about smaller units of time? They had identified other stars and constellations that appeared at different times and they used that new knowledge to split their year into 10 day long weeks.


They also realised that they could use the way the stars appeared in the night sky  to split the night into 12 equal parts, they then also split the day into 12 hours parts. This gave us the 24 hour day!.


The Egyptians used how shadows change during the day to track time - archaeologists have found evidence for shadow clocks dating back 3500 years. (refer to the experiment from day 3)


Another early civilization - that of the Babylonians had made huge advances in mathematics and they split the day down even further into hours and minutes. Shadow clocks would not work to this level of accuracy and so people began to use sundials.


Instead of measuring the length of shadows like shadow clocks sundials look at the direction in which  the shadow is pointing. Sundials are based on your latitude so you must adjust your sundial to match your position on the earth!.


Activity 1 - Make a sundial (krokotak)


Activity 2 - Practice telling the time with our clock stamp

Day 5


Recap Questions


What is a lunar cycle?


How did early people try to use the lunar cycles to create a calendar?


What is the problem with using the lunar cycle to create a calendar?


How did the Egyptians change their calendar over time?


How did the month of July get its name?


How did the month of August get its name?


What is the name of the calendar we use today?


How did the Egyptians give us the 24 hour clock?


Which civilization was the first to split the day hours into minutes and seconds?


Telling the time after dark


Sundials and shadow clocks have one major problem - they only work when there is sun!


The Egyptians solved this problem by using water clocks. 

Water clocks are basically containers which have a small hole in  to allow water to drip very slowly out. During he day at a time you can use another form of timekeeping (sundial for example) you would time how long it took your container to empty. Then during night time you would know that your water clock took a certain amount of time to empty and so could keep track of time that way.


Water clocks were used for a long time with some getting so advance that they had bells and gongs to mark the passing hours. 


A famous water clock in the tower of the winds in Athens. (youtube)