Transcript multiplication learn zillions ppt lesson

Which of these addition sentences is the
same as 4 x 3?
4+3
3+4+3+4
4+4+4+4
3 + 3 + 3 +3
In this lesson you will learn solve
multiplication problems by
writing them as repeated
addition.
Let’s Review
Addition is finding the total amount.
3+4=7
Multiplication is also finding a total amount, but of
equal groups.
Multiplication is repeated addition.
A Common Mistake
A common mistake is to add the wrong numbers.
2x4=
2+2=
4+4+4+4=
2+4+2+4=
Core Lesson
There are two ways to write most multiplication
expressions as repeated addition.
2x4=8
2+2+2+2=8
4+4=8
Core Lesson
3x7=
Number of groups
Amount in each group
(number of times you
(number you add)
add)
7 + 7 + 7 = 21
3 + 3 + 3 + 3 + 3 + 3 + 3 = 21
Core Lesson
On Halloween, Casper gets 2 pieces of candy from
each of the six houses he visits. How many pieces
of candy did he receive in all?
Core Lesson
On Halloween, Casper gets 2 pieces of candy from
each of the six houses he visits. How many pieces
of candy did he receive in all?
6x2=?
Number of times you
add
2 + 2 + 2 + 2 + 2 + 2 = 12
Number you add
6 + 6 = 12
Core Lesson
Which of these addition sentences
is the same as 4 x 3?
4+3
3+4+3+4
4+4+4+4
3 + 3 + 3 +3
In this lesson you learned to
solve multiplication problems by
writing them as repeated
addition.
Guided Practice
Which addition expression below represents
4 x 6?
Number of times
Number you
you add
add
a) 4 + 4 + 4 + 4
b) 6 + 6 + 6 + 6 + 6 + 6
c) 6 + 6 + 6 + 6
d) 4 + 6 + 4 + 6
Extension Activities
Ask students when only one addition expression
can be written for a multiplication problem. (ex.
6 x 6) What do these equations have in
common? You can explain that we have a special
name for these numbers (squares), and make a
visual connection between multiplication and
geometry. Also, what numbers cannot be made
as a result of repeated addition? (primes)
Extension Activities
Have students come up with their own multiple
choice questions with two correct ways to write
multiplication as repeated addition, and one
incorrect way.
Quick Quiz
How would you write 3 x 5 as repeated
addition two different ways?
6 + 6 + 6 + 6 is equivalent to what
multiplication expression?