Transcript Decimats - Teacher Tools

Decimats
I am learning to identify equivalent fractions and to name fractions
as decimals.
Equivalent means equal or
the same.
Below is a sheet of paper that has been folded in half. One half has
been shaded red.
1
is red
2
Now I am going to fold the
paper in half again.
You can see it is now cut into quarters. 2 quarters of the paper is
shaded red.
1
2
is the same as
They are equivalent.
2
4
Can you spot any pattern between these fractions?
You can see from this that
1
2
X2
X2
2
4
The numerator is twice as big.
The denominator is twice as big.
Below is a sheet of paper that has been folded into thirds. One third
has been shaded red. 1 is red
3
Now I am going to fold the paper two more times
so that it is in ninths.
You can see it is now cut into ninths. 3 ninths of
the paper is shaded red.
You can see from this that
1
3
is the same as
3
9
They are equivalent.
Can you spot any pattern between these fractions?
1
3
X3
X3
3
9
The numerator is three times as big.
The denominator is three times as big.
Now lets try to work out how many tenths, hundredths and
thousandths some fractions are equivalent to.
2
of the shape below is red.
5
How we could change this shape into tenths?
4
2
By folding it in half you can see that
is equivalent to 10
5
2
5
4
X2
10
Now let’s change
4
into hundredths.
10
We can do this by splitting each of the tenths into ten pieces. That
means the whole shape will be split into hundredths.
So every tenth would look like this.
There are 4 red tenths so 4 X 10 = 40
2
5
X2
4
40
X 10
10
100
40
100
Let’s go one step further and work out how many thousandths this is
the same as.
This was 2
5
Then we changed it into
4
10
40
Then we changed it into
by splitting each piece into ten more pieces.
100
If we split every hundredth into ten pieces we would then have made
thousandths.
There are 40 hundredths. If we split every one on these hundredths into
ten pieces we would have 400 thousandths.
40 X 10 = 400. so….
2
5
X2
4
40
40
X 10
X 10
10
1000
100
Notice how if you multiply the numerator and the denominator by the
same amount you always get an equivalent fraction.
This is helpful when you are trying to change a fraction into tenths,
hundredths or thousandths so you can show it as a decimal.
3
5
X2
6
10
2
25
X4
8
100
0.08
9
20
X5
45
100
0.45
0.6
Now try these questions on your own.
Click again when you have worked out all your answers.
1)
2)
3)
4)
5)
1
=
4
6)
?
3
= 21
7
9
21
7)
1
3
=
?
9
3
9
8)
4
5
?
=
10
8
10
20
100
9)
?
2
=
33
11
6
33
40
90
10)
?
8
2
8
3
?
=
5
20
12
20
2
?
=
8
16
4
16
5
?
=
25 100
?
90
4
9
?
300
3
=
600 600
6
Need some more practise? Try Pg30 & 31 of Teacher Tools Fractions,
Decimals and Percentages Book Numeracy resources
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