Lead In:

In our books we had a few minutes to write down everything we knew about our system for measuring time in years. Some children chose to write a list of dot point ideas and others chose to draw a timeline highlighting BC /AD and (as hoped) the year zero.

Whole Class Enquiry:

As a whole class, we started sharing what we knew about how our 'years system' works. When one of the students shared 'Everything before the year zero is BC' I asked the class whether there is a year zero or not. Those of us who thought there was a year zero were asked to stand up. Everyone did except for two students..... So that became our new direction to investigate.

We all knew that B.C meant 'Before Christ', but when asked what does A.D mean we had a few different theories. One group's theory was 'After Dinosaurs' so we drew a dinosaur on our timeline far away from the Big Bang Theory which we had already placed on it at the beginning of our discussion.

Another student's theory was 'After (the) Death of Christ' and so we explored whether that makes sense or not with our timeline on the board, we drew a line to indicate when Jesus was born (around the year zero with a question mark placed above it). We then draw another line a bit further down and I wrote 'After Christ died'. I asked them to look at our number line to see what they noticed. Eventually someone explained that it doesn't make sense. If Jesus was born in the year zero and everything before that was BC and then he died later and everything after that becomes A.D then what do we call those years in between when he was alive?!?! Exactly! What can we call them? Can our system for measuring time have a small gap? Does that make mathematical sense?

Another student then shared how he had thought A.D was a Latin word, but he couldn't remember exactly what it stood for. Several suggestions that we need to google it then came up so that is waa we did. We found out A.D is Latin for Anno Domino meaning in the Year of the Lord.

With this new knowledge, we then looked at our timeline again. If the moment Jesus was born becomes 'In the Year of our Lord' and the moment before he was born was BC, then can the year zero exist?

A few students agreed with one idea- that the year Jesus was born must be the year one. Though, someone else debated that by connecting how when we are born, we don't start as 1 year old, we start in months and eventually we become 1. Therefore, could Jesus be 1 year old as soon as he was born. This, we agreed, was an interesting connection which then sparked another student's connection: This is like the a.m and p.m difficulty with midnight (see below ++)

So, then I posed the question, let's say the year zero does not exist. Based on what we see here about Jesus' birth, how might the time system work? One student theorised that perhaps there is a 1 BC and then the next year is 1AD and that that would make sense given what we now knew BC and AD stood for. Most of us agreed that this new theory we had made sense.

But, quickly loads of our questions started flying around in our discussion such as:

° But what about people in other countries who aren't Christian? Do they use this measurement system too? We debated this idea for a while with some sharing how they had heard of a lunar calendar being used in Asia, so we added that to our wonder wall to investigate further later. We then talked about the terms B.C.E and C.E and how these are helpful for people who aren't Christian.

° Are the BC numbers negative numbers? The connection here was how we use negative numbers with the temperature so we had quite a lively debate whether BC years are considered negative years or not. Can a year be negative? If not, then why can a temperature be a negative?

Reflection:

From testing out our theories in this discussion, we generated quite a few questions to our wonder wall.

++A few days before we had discussed whether we thought midnight was a.m or p.m. We had eventually come up with the theory that technically the stroke of midnight should be p.m. But the moment the second hand moves from the strike of midnight, it is technically past midnight even if by a second.

In our books we had a few minutes to write down everything we knew about our system for measuring time in years. Some children chose to write a list of dot point ideas and others chose to draw a timeline highlighting BC /AD and (as hoped) the year zero.

Whole Class Enquiry:

As a whole class, we started sharing what we knew about how our 'years system' works. When one of the students shared 'Everything before the year zero is BC' I asked the class whether there is a year zero or not. Those of us who thought there was a year zero were asked to stand up. Everyone did except for two students..... So that became our new direction to investigate.

We all knew that B.C meant 'Before Christ', but when asked what does A.D mean we had a few different theories. One group's theory was 'After Dinosaurs' so we drew a dinosaur on our timeline far away from the Big Bang Theory which we had already placed on it at the beginning of our discussion.

Another student's theory was 'After (the) Death of Christ' and so we explored whether that makes sense or not with our timeline on the board, we drew a line to indicate when Jesus was born (around the year zero with a question mark placed above it). We then draw another line a bit further down and I wrote 'After Christ died'. I asked them to look at our number line to see what they noticed. Eventually someone explained that it doesn't make sense. If Jesus was born in the year zero and everything before that was BC and then he died later and everything after that becomes A.D then what do we call those years in between when he was alive?!?! Exactly! What can we call them? Can our system for measuring time have a small gap? Does that make mathematical sense?

Another student then shared how he had thought A.D was a Latin word, but he couldn't remember exactly what it stood for. Several suggestions that we need to google it then came up so that is waa we did. We found out A.D is Latin for Anno Domino meaning in the Year of the Lord.

With this new knowledge, we then looked at our timeline again. If the moment Jesus was born becomes 'In the Year of our Lord' and the moment before he was born was BC, then can the year zero exist?

A few students agreed with one idea- that the year Jesus was born must be the year one. Though, someone else debated that by connecting how when we are born, we don't start as 1 year old, we start in months and eventually we become 1. Therefore, could Jesus be 1 year old as soon as he was born. This, we agreed, was an interesting connection which then sparked another student's connection: This is like the a.m and p.m difficulty with midnight (see below ++)

So, then I posed the question, let's say the year zero does not exist. Based on what we see here about Jesus' birth, how might the time system work? One student theorised that perhaps there is a 1 BC and then the next year is 1AD and that that would make sense given what we now knew BC and AD stood for. Most of us agreed that this new theory we had made sense.

But, quickly loads of our questions started flying around in our discussion such as:

° But what about people in other countries who aren't Christian? Do they use this measurement system too? We debated this idea for a while with some sharing how they had heard of a lunar calendar being used in Asia, so we added that to our wonder wall to investigate further later. We then talked about the terms B.C.E and C.E and how these are helpful for people who aren't Christian.

° Are the BC numbers negative numbers? The connection here was how we use negative numbers with the temperature so we had quite a lively debate whether BC years are considered negative years or not. Can a year be negative? If not, then why can a temperature be a negative?

Reflection:

From testing out our theories in this discussion, we generated quite a few questions to our wonder wall.

++A few days before we had discussed whether we thought midnight was a.m or p.m. We had eventually come up with the theory that technically the stroke of midnight should be p.m. But the moment the second hand moves from the strike of midnight, it is technically past midnight even if by a second.