Lattice Method

Mr. Bui5th grade SEIHorace Mann Elementary

Lattice Method

Objective: By the end of this presentation I can multiply using the lattice method

Lattice versus Traditional

Like your parents and countless others, I started by using the traditional method.After learning and becoming proficient in both methods, I prefer the Lattice myself in terms of speed and accuracy

Lattice versus Traditional

The traditional method requires several memorization steps and can get pretty messy when regrouping is involvedIt also requires you to line up the place value

Lattice versus Traditional

The lattice method requires you to just know how to set up the grid

Lattice versus Partial Product

There is a third method called the Partial Product Method which is also another way to multiply

We will NOT be covering this method.

Lattice MethodWhy

We use the Lattice Method becauseIt is fasterUses a visual grid

One downside is that it requires precise drawing of the grid

Lattice MethodHow

The Lattice is best done with colors and highlighters at first because it takes practice to become efficient at it

The best way to show the Lattice Method is through an example

Let us do something simple:

54 x 12

Lattice MethodExample

Lattice Method

Let us break the numbers down and understand it a bit better.

54 x 1254 has 2 digits (a 5 for the tens place and a 4 for the ones)

12 has 2 digits (a 1 for the tens place and a 2 for the ones)

Lattice Method

54 x 1254 12

Lattice Method

54 x 125 4

1

2

Insert diagonal lines for each box.

Lattice Method

54 x 125 4

1

2

Multiply one set

40

4 x 1 = 4

Put product in appropriate triangle

There are zero tens in the product, and four ones

5 41

2

Lattice Method

54 x 12

Multiply one set

40

4 x 2 = 8

Put product in appropriate triangle

There are zero tens in the product, and eight ones

0

8

5 41

2

Lattice Method

54 x 12

Multiply one set

40

5 x 1 = 5

Put product in appropriate triangle

There are zero tens in the product, and five ones

0

8

0

5

5 41

2

Lattice Method

54 x 12

Multiply one set

40

5 x 2 = 10

Put product in appropriate triangle

There are one tens in the product, and zero ones

0

8

0

5

0

1

5 41

2

Lattice Method

54 x 12

Now we just got to add the numbers diagonally.

40

0

8

0

5

0

1

8

8 + nothing is 8

5 41

2

Lattice Method

54 x 12

Now we just got to add the numbers diagonally.

40

0

8

0

5

0

1

8

4 + 0 + 0 = 4

4

5 41

2

Lattice Method

54 x 12

Now we just got to add the numbers diagonally.

40

0

8

0

5

0

1

8

5 + 1 + 0 = 6

46

5 41

2

Lattice Method

54 x 12

Now we just got to add the numbers diagonally.

40

0

8

0

5

0

1

8

0+ 0 = 0

46

0

5 41

2

Lattice Method

54 x 12

Re-write the answers following the arrow

40

0

8

0

5

0

1

846

00648

5 41

2

Lattice Method

54 x 12

We can drop the extra zero on the left

40

0

8

0

5

0

1

846

0648

5 41

2

Lattice Method

54 x 12 =

We can drop the extra zero on the left

40

0

8

0

5

0

1

846

0648

Lattice Method

What happens when you add diagonally and it is 10 or more?

5 44

9

Lattice Method

54 x 12 =

Add it diagonally

61

3

6

2

0

5

4

6

6 + 3 + 5 = 14

14

Regroup the tens into the next diagonal

5 44

9

Lattice Method

54 x 12 =

Add it diagonally

61

3

6

2

0

5

4

6

1 + 0 + 4 + 1 = 6

1

4

6

5 44

9

Lattice Method

54 x 12 =

Add it diagonally

61

3

6

2

0

5

4

6

2 + nothing = 2

1

4

6

2

5 44

9

Lattice Method

54 x 12 =

Add it diagonally

61

3

6

2

0

5

4

6

2 + nothing = 2

1

4

6

2

Lattice Method

That’s pretty much it!