Multiplying 3 Digits by 3 Digits

Multiplying 3 Digits by 3 Digits

Review

To review what we have already discussed last week, whenever we multiply 3 digit numbers with other 3 digit numbers, we need to be mindful of the placeholders, and how many placeholders go on each line when solving.

The first line gets NO placeholder, the second line will get 1 place holder, and the third line will get 2 place holders.

Example:

Here we can see the placeholders colored in red.

For each line as we increase, there is more placeholders added on the line.

Multiple Choice

A place holder is represented as:

• a blank

• a zero

• a one

Multiple Choice

For each row added in the multiplication process we add another placeholder.

• True

• False

Multiple Choice

In this problem, how many rows will there be?

230 x 12

• 1 row

• 2 rows

• 3 rows

• 4 rows

Multiple Choice

In this problem, how many rows will there be?

230 x 120

• 1 row

• 2 rows

• 3 rows

• 4 rows

Multiple Choice

Now, find the answer for 230 x 120

• 27,600

• 2,760

• 28,600

• 2,860

Now apply this to multiplying decimals

The same rules of place holders will apply whenever we are multiplying decimals. Just we will have to remember to place the decimal in the FINAL answer once we are done.

We cannot place the decimal until we have finished multiplying and got the final answer, otherwise it will greatly change the answer.

Open Ended

How many times will I move the decimal in the answer for this problem? 12.3 x 2.55

Multiple Choice

Jackie earns $8.95 per hour.  This week she worked 7.5 hours.  How much did she earn this week?

• $67.125
• $67.12
• $67.13
• $68.00

Multiple Choice

Find the answer for: 6.39 x 1.25

• 5.112

• 79.875

• 7.9875

• 51.12