Transcript Multiply using the Partial Product and the Lattice Method

By John Frezza
Click here to begin slide show
Confusion!
76
?
?
?
15
?
60
Difficult!
?
Multiplying two digit and three numbers can be
a scary proposition for most children. By using
either the partial product method or the lattice
method it allows students to take a more
organized, step by step approach!
Either of these methods will ease the students
apprehension and the best part is, students can
choose the one they feel most comfortable with.
Lets begin with the
partial products
method.
Lets multiply
45
x 35
By breaking down the numbers you are
multiplying by place value the numbers become
easier to manage. Then students can think in
terms of multiplying using base 10 strategies.
x
40
5
Tens
30
Ones
5
Students can then make an easier calculation.
Once you have multiplied each number, it’s
time to add the products.
1,350
+
225
Next you simply add the sums together and
your answer is 1,575!
1,350
+
225 = 1,575
You try the Partial Product Method
62 x 45
x
40
2,400
Tens
60
Ones
2
Select one
Select one
80
200
800
Select one
5
30
300
First do 40 x 60, then 40 x 2
80
8,000
Select one
80
100
10
1,000
Followed by 5 x60, then 5x2
Sorry! …….Try Again
You’re Correct!
x
Tens
60
40
2,400
5
continue
Ones
2
You’re Correct!
x
Tens
60
Ones
2
40
2,400
80
5
continue
You’re Correct!
x
Tens
60
Ones
2
40
2,400
80
5
300
continue
You’re Correct!
x
Tens
60
Ones
2
40
2,400
80
5
+ 300
+ 10
Now just add the products together
90
2,700
+
= 2,790
Then add the sums
Go to next slide!
Next, lets explore the
lattice method using
the same numbers,
45 and 35.
By breaking the numbers into these boxes the
multiplication process becomes more manageable
for students.
3
5
1
2
4
2
1
0
2
5
5
1,
5
7
5
5
Once you have completed the multiplication
process, it’s then simply a matter of adding
diagonally!
10
24
3rd
6x4=
12
30
6
2
1st
2x4=
4th
6x5=
2nd
5
8
12
6
4
8
11
You’re Turn!
Try the lattice, you’ll love it
62 x 45
2x5=
7
10
15
NOPE!
TRY AGAIN!
Very Good!
62 x 45
10
24
6x4=
6
8
2
12
6
4
0
8
2x4=
8
11
12
7
6x5=
30
5
2x5=
10
15
continue
Very Good!
62 x 45
10
24
6x4=
8
6
2
2x4=
6
4
8
11
12
12
7
6x5=
1
5
0
30
continue
2x5=
10
15
Very Good!
62 x 45
10
24
6
6x4=
2
2
8
8
2x4=
12
6
4
4
11
12
7
6x5=
30
5
2x5=
10
15
continue
Very Good!
You Are
Ready to
add!
62 x 45
6
2
2
0
8
4
6x5=
4
1
3
0
5
0
Remember to add diagonally!
6
2
2
0
4
+
+
8
4
+
=
+
1
3
5
+
=
2,
0
=
7
9
The
answer is!
0
+
=
0
= 2,790
In my experience, especially as a teacher of students with
special needs, most students choose the lattice method to
perform multiplication problems containing numbers
with two or more digits.
I believe this option truly lets the student take the number
in smaller pieces and makes the operation more
manageable for them.