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G'day, I'm Dr Peter Price of Classroom Professor. Welcome to video number "41" in the Free Math
Worksheet Series. And a special welcome back to teachers in Australia, New Zealand and
South Africa who've been on their summer break and this is the first video in the series
that's after the summer. So the other thing that's new this week is, unlike previous videos
where I've talked about worksheets from our eBook series on developing number fluency,
this week is the very first time that I can talk to you about our new set of resources
that are called, "Classroom Professor Gadgets" now I don't have time to go in a full spill
on this but basically it's interactive software for teaching mathematics, and it's a collection
of tools, so each tool does a specific job and we think it does it quite well. And most
importantly it supports students developing their mathematical thinking and that of course
is our philosophy, the pedagogy that we teach and recommend for learning mathematics generally,
and so the software will enable students to do that very thing, develop their mathematical
thinking. So this week's set of worksheets comes from a brand new set that is bundled
with the gadget called "Number Facts", so I'll be contacting everybody on the list about
the gadgets when they're fully available, but for now just a quick introduction and
we'll get straight in to it. So we're looking at "Number Fact Families" now I talked about
this in the last, not last week but the 2 weeks prior to that, so I actually won't take
very long to talk about this today, but I'll just put a different slant on it. The idea
of number fact families is that there are some facts that if you like, belong together,
and so it can help students to be alerted to that fact, so that they can learn facts
in groups if you like, or you know when they've done all the strategies it can help to reinforce
their knowledge, I wouldn't start with this families but ones they know them they can
start to think about you know, clamping the facts together if you like. So here's a visual
representation, we've got some counters here and some counters there, and if we're adding,
which is the focus of these worksheets, everybody knows it doesn't matter which order that you
add them, we can reverse the two sets of counters or objects and we'll get exactly the same
result. So this happens to be, "8 + 5" and we know that we can turn that around so we
have what we call "Turn around facts". And the other fancy word that we sometimes use,
although not with students, is that this is an example of the "Commutative Principle".
So it's the fact that you can turn the facts around and o them in opposite directions,
and of course that is a property of both addition and multiplication, so we can do the turn
arounds in both those operations, clearly not in subtraction or division but in those
two. So there's two facts that we can find that belong together quite obviously, the
other thing we can do of course is to think about what we would get if we did the reverse
operation of subtraction. "8 + 5 is 13, so what would happen if we started with 13 - 8?"
"8 +5 is 13, what would happen if we took 8 away for 13?" obviously this is the 8, we
would have 5 left, "What would happen if we started with 13 and took away the 5?" we will
have the 8 left. And so there's a set of 4 number facts that use the same 3 numbers over
and over again, the 5, the 8 and the 13, and so we call that a number fact family. Now
I don't have the software available right now to show it on the video, but just with
a quick visual representation, the number fact software has a grid, and I think it actually
goes up to 10 and I just did this quick visual mock-up showing how it looks, so along the
top of course it has numbers from 0 up to, and as I've said I think it goes up to 10
and down the left hand side the same thing. And then we can find all the number facts,
and so if this is an addition grid then if we're looking for 8 + 5, we can say, "8 along
the top, 5 down the side" and that would be just there, and there will be a 13 there and
so we look at the intersection of the row and the column. But we can also find another
one because if we look at the 5 here, and the 8 there, then there's a second intersection
with the same number fact and of course again it's the turnaround fact. And so the software
allows you to find those turnarounds, the other thing it will do is on the side, and
I apologies I can't remember which side, because we're still in the design phase, I think it's
on this side, on the side there's a little box with a number fact family in the box and
so it will list the 4 number facts. So that's just one of the features in the program, the
worksheets themselves reinforce that idea so the worksheets are designed to supplement
the use of the software, and so in the set of worksheets that you'll see this week there
are a number of different strategies on each page of the set of worksheets but in each
one it asks the students find the other number facts that go together to make out number
fact families. So that's it for this week, I hope you've enjoyed the video, and I look
forward to talking to you next time.