Transcript Lattice Multiplication

Do Now
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Order the following fractions from least to
greatest:
½ , 1/8, 1/3, 1/9
2/3, 1/6, 3/6, 2/5, 4/7
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Homework: lattice multiplication worksheet
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Lattice Multiplication
By Mrs. Heter
Standard/ Objective
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6.N.17 Multiply and divide fractions with
unlike denominators
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Objective: SWBAT multiply 2 digit by 2 digit
numbers using the lattice method.
Flow of the Day
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Do Now 5 min
Intro to new material 15 min
Guided practice 15 min
Independent practice 20 min
Exit Slip 5 min
Upon completion of this exercise, you
will:
Upon completion of this exercise, you
will:
•Discover the history of lattice multiplication;
Upon completion of this exercise, you
will:
•Discover the history of lattice multiplication;
•Identify the four step process for completing a 2 by 1
lattice;
Upon completion of this exercise, you
will:
•Discover the history of lattice multiplication;
•Identify the four step process for completing a 2 by 1
lattice;
•Construct your own 2 by 1 lattice grid;
Upon completion of this exercise, you
will:
•Discover the history of lattice multiplication;
•Identify the four step process for completing a 2 by 1
lattice;
•Construct your own 2 by 1 lattice grid;
•Apply the Lattice Method to multiplication problems
So, what is Lattice Multiplication,
anyway?
So, what is Lattice Multiplication,
anyway?
Lattice multiplication is a method of
multiplication that will work for all multidigit multiplication problems! Lattice
keeps your numbers organized and
provides a systematic way to solve
multiplication problems.
Is Lattice Multiplication New?
Is Lattice Multiplication New?
NO! In fact, the Lattice method of multiplication
appears in the first printed arithmetic book.
Printed in Treviso, Italy in 1478 this book
shows this exact method as well as some
variations of the long multiplication algorithm
commonly taught today.
COOL!
4 Simple Steps to Lattice Multiplication
1. Make the grid/ lattice
2. Write the factors outside the
grid
3. Multiply
4. Add to get your answer
Step One: Make the Lattice Grid
First draw a box and
divide it into 2 equal
sections.
Step One: Make the Lattice Grid
Next, divide those boxes
diagonally from the top
right to the bottom left
corner.
Step Two: Write the factors on the grid
Now what? Simple, ask someone to give you a
multi-digit multiplication problem to solve!
Now add these numbers to the grid.
43 x 5 = ?
Fill in the Lattice
Fill in the numbers like
this…
4
3
5
Step Three: Multiply
Now multiply!
43 x 5 = ?
Then Multiply the Outside!
First multiply 5x3 and
write your answer in the
lattice as shown.
4
3
1
5
5
Then Multiply the Outside!
Next, multiply 5x4. Write
your answer in the top
left box of your lattice
2
grid.
4
3
1
5
0
5
Wait! You’re Not Finished Yet!
Step Four: Add the Inside
Finally, add the
numbers in the
diagonals to get the
solution.
5 is all by itself so simply bring
that number down.
4
2
3
1
5
0
5
5
Step Four: Add the Inside
Finally, add the
numbers in the
diagonals to get the
solution.
Next, add 1 + 0, and write the
sum under the lattice.
4
2
3
1
5
0
1
5
5
Step Four: Add the Inside
Finally, add the
numbers in the
diagonals to get the
solution.
4
2
1
5
0
Finally, bring down the 2.
2
3
1
5
5
Now you’ve got your answer!
43 x 5 = 215
Now You Try It.
Using the graph paper in
front of you, draw a
square around any two
of the blocks on your
paper.
Now You Try It.
Next, divide those boxes
diagonally from the top
right to the bottom left
corner.
Fill in the Lattice
Fill in the numbers like
this…
3
9
6
Then Multiply the Outside!
First multiply 6x9 and
write your answer in the
lattice as shown.
3
9
5
6
4
Then Multiply the Outside!
Next, multiply 6x3. Write
your answer in the top
left box of your lattice
1
grid.
3
9
5
6
8
4
Add the Inside
Finally, add the
numbers in the
diagonals to get the
solution.
4 is all by itself so simply bring
that number down.
3
1
9
5
6
8
4
4
Add the Inside
Finally, add the
numbers in the
diagonals to get the
solution.
Next, add 5 + 8, and write the
sum under the lattice.
3
1
1
9
5
6
8
3
4
4
Step Three: Add the Inside
Finally, add the
numbers in the
diagonals to get
the solution.
3
1
1
5
6
8
Finally, add the 1 + 1
And write the sum below
the lattice.
9
2
3
4
4
Now you’ve got your answer!
39 x 6 = 234
Let’s Practice Together!
Practice is FUN!
Try 71 x 3
Are you ready
for more?????
Ready, Set, Let’s Solve Lattice
Multiplication Problems!
Please open your math journal to page 231
Try 8 x 45
Try 5 x 23
Try 6 x 431
Hmmm, what will we need
to do differently to multiply
a THREE digit number?
Try 6 x 431
Let’s Take a Quick Lattice
Multiplication Quiz to see
how much you
remember!
Yes or No?
CLAP your hands ONE TIME for YES.
STOMP your feet ONE TIME for NO.
Lattice multiplication is a NEW
method of multiplying
numbers?
No!
Lattice multiplication has been
in use since the late 1400’s!
Yes or No?
CLAP your hands ONE TIME for YES.
STOMP your feet ONE TIME for NO.
The process for solving Lattice
Multiplication involves 4 steps.
4 Simple Steps to Lattice Multiplication
1. Make the grid/ lattice
4 Simple Steps to Lattice Multiplication
1. Make the grid/ lattice
2. Write the factors on the
outside of the grid
4 Simple Steps to Lattice Multiplication
1. Make the grid/ lattice
2. Write the factors on the
outside of the grid
3. Multiply
4 Simple Steps to Lattice Multiplication
1. Make the grid/ lattice
2. Write the factors on the
outside of the grid
3. Multiply
4. Add to get your answer
Congratulations!
You’ve just learned how
to solve multi-digit
multiplication problems
using the Lattice
Multiplication Algorithm!
Congratulations!
Now, finish the problems
on the right column of
page 231. Ask your seat
mate or raise your hand
if you need assistance.