Lesson Plan of Distributive Law Mathematics Grade V
Lesson Plan of Distributive Law
Mathematics Grade V
Students’ Learning Outcomes
·
Verify distributive laws
Information for Teacher
·
Distributive law collects
multiplication and addition subtraction operations:
o Distributive law w.r.t addition x(b + c) = a × b+
a
c
c
o Distributive law w .r.t subtraction ax(b – c) =
a × b – a x c
·
While teaching the lesson,
also consult textbook at all steps where and when applicable.
Material / Resources
Chalk/marker, board, textbook, duster
Worm up activity
·
Write ‘Distributive Laws” on
the top of the board.
·
Ask students if they have any
idea what it is?
·
Tell students that this law
(sometimes called property )states that you get the same answer when you
multiply a number by a group of numbers added together as when you do each
multiplication separately.
Example: 3x (2+4) =3x2 +3x4
so the “3” can be “distributed” over the “2+4” into 3 times 2 and 3 times 4.
·
Show it with help of the
following figure:
3 x (2 + 4) (3 x 2) +
(3 x 4)
Development
Activity 1
·
Draw the following shape on
the board and tell students that this figure represents the area of rectangle
with length b + c and width a
·
Hence area of this rectangle
is = a x ( b + c) or a(b + c)
·
This can be split into two
parts as follows:
·
Now the sum of the area of
both rectangles is a b + ac
·
Because both are parts of
that rectangle, so we can write: a( b +
c) = a b + ac
·
Give paper strips to students
in groups to verify it for themselves.
Activity 2
·
Tell students that it is very
convenient to use distributive law for quick multiplication.
·
Tell students that I want to
multiply 12 x 19, and I used a quick method to do it. I multiplied 12 by 20.
Well 12 x 20 is easy, it’s 240. But, I added one more 12 than I needed, so I’ll
take it away from 240 to give me 228. =
·
Similarly as students how to
do
·
Solve 2 more examples1: 4 x 27
= 4(20+ 7)
= 4(20) + (7)
= 80 + 28 = 108
Example 2: obtain 4 x 102 using distributive law
Solution: We know, 102 = 100
+ 2
So, 4 x 10 = 4 x (100 + 2)
= (4 x 100) + (4x 2)
= 400 + 8 = 408
Activity 3
·
Now divide students in two
groups.
·
Each group will suggest a
multiplication sum like given in the examples of previous activity, for the
other group as challenge.
·
Other group will solve in
their notebooks.
·
Each group will solve at
least 5 questions.
·
Help students if they are
unable to do any question.
·
These multiplication sums can
be selected from textbook exercise as well.
Sum up / Conclusion
·
The distributive laws lets
you multiply a sum by multiplying each added separately and then add the
products.
·
Quick multiplication can be
done through distributive laws.
·
The distributive property
helps with mental math.
·
A quick multiplication is:
4 x 53
=
(4 + 50) + (4 x 3)
= 200 + 12 = 212
Assessment
·
Students will be given
following statement questions to apply their understanding of Distributive Law.
·
Mother prepared 12 bags of
sweets for birthday party of Semi. In each bag she puts 5 chocolate and 14
candies. How many sweets did mother buy?
·
A necklace made of
alternating 4 grey beads and 2 black beads is shown. Explain the way one can
find, how many beads are there in the necklace?
Follow up
·
Solve following questions by
applying Distributive Laws.
1.
In each fish tank there are 7
gold fish and 6 black fish. There are 8 fish tanks. How many fish are there
altogether?
2.
There are 3 tables. On each
table there are 6 lemons glasses and 5 cold drink bottles. How many drinks are
there altogether?
3.
Assign some questions from
textbook to do as homework.
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