Multiplying Decimals

Multiplying Decimals

Poll

How do you feel about multiplying decimals?

(ex: could you answer 1.54 x 2.37 without a calculator?)

• I don't really remember how to start

• I kind of remember that and feel like I could probably get it right with help

• I can do that right now and am 100% confident I have the right answer

Reminders:

• You do not need to line up the decimal points when you are multiplying decimals

• line up the numbers, as you would if they were whole numbers, and multiply as if it were a multi-digit problem

• Once you have finished, count the number of decimal places in both factors and place the decimal in that spot in your final answer

Let's Try

1.67 x 2.3

5.1 x 1.8

6.3(0.6)

What happens if there is negatives involved?

Multiple Choice

When multiplying 2 numbers, if they have the same signs, the answer is...

• positive

• negative

Multiple Choice

When multiplying 2 numbers, if they have different signs, the answer is...

• positive

• negative

So don't change a thing, just decide if your answer is positive or negative at the end

-2.5 x 3.6

Multiple Choice

(-2.5 x 3.6) will this answer be positive or negative?

• positive

• negative

Multiple Choice

-5.78 x 3.5

• -0.223

• -2.23

• 22.3

• -20.23

Multiple Choice

-1.2 x -2.1

• -25.2

• 0.36

• 2.52

• -3.6

Multiple Choice

0.3 x -0.5

• -0.15

• 0.15

• -1.5

• 15.0

Open Ended

-2.4 x -0.7

Poll

How do you feel about multiplying decimals?

(ex: could you answer 1.54 x 2.37 without a calculator?)

• I don't really remember how to start

• I kind of remember that and feel like I could probably get it right with help

• I can do that right now and am 100% confident I have the right answer