Let’s look at several methods including the Lattice method.

**Traditional Method:**

Step 1.

Step 1.

Multiply the ones. ( 4 x 2 =8)

3

**4**

X

**2**

---------------

...8 (The periods in front of the eight and any other number in this article can be ignored. They are for formatting purposes only)

**Step 2.**

Multiply 2 by the tens place. Notice the 6 is written in the tens place because you are actually multiplying 30 x 2 = 60 and thus end up with 6 tens.

**3**4

x

**2**

----------------

**6**8

We’re done!

**Example 2**

Multiply 8 x 7 = 56. since the largest number any place value can hold is 9, we must leave the six in the ones place, but carry the 5 to the tens place. Notice the”+” in front of the five to remind us to add it later.

**+5**

.. 3

**8**

X

**7**

----------------

...

**6**

**Step 2**

Multiply 7 times the tens place and add the number carried in the last step.

(7 x 3 = 21 + 5 = 26 tens)

Again, the answer is larger than 9, so write the 6 in the tens place. Since, there is no place to carry the 2, place it in front of the 6.

**+5**

..38

..3

X

**7**

----------------

**26**6

We’re done!

Now, let’s multiply a two-digit number by a two-digit number.

One Way: This method uses the expanded notation.

(Ignore the periods in front of the numbers. They are for formatting purposes only.)

5 6

x 4 3

-------

…18 < --- 6 x 3

..150 < --- 50 x 3

..240 < --- 6 x 40

2000 < --- 50 x 4

--------

2408 < --- (Add 18 +150 + 240 + 2000)

**Traditional Method:**

Step 1

Step 1

**+1**

..5 6

..5 6

X 4

**3**

----------

168 < --- 56 x 3

**Step 2**

**+2**

.. 5 6

X 43

.. 5 6

X 4

------------

168 < --- 56 x 3

2240 < --- 56 x 40

--------

2408 < ---- (168 + 2240)

Lattice Method

Let’s use the same factors, 56 x 43

Write factors outside of the box.

Box a – enter answer for 5 x 4 = 20

Box b – enter answer for 6 x 4 = 24

Box c – enter answer for 5 x 3 =15

Box d – enter answer for 6 x 3 = 18

Look below:

Next, Add numbers in the diagonals.

The answer is 2,408

56 x 43 = 2,408

Which method do you prefer?