multiply with decimals standard uw.gap.5.m.nbt.07 add, subtract, multiply, and divide decimals to...
TRANSCRIPT
Multiply with decimals
Standard UW.GAP.5.M.NBT.07 Add, subtract, multiply, and divide decimals to hundredths using concrete models or drawing and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used.
Essential Questions1. What is addition? How do you add decimals?
2. What is subtraction? How do you subtract decimals?
3. What is multiplication? How do you use a model and partial products to represent multiplying decimals?
4. What is division? How do you use a model and partial products to represent dividing decimals?
Set....
Think about the strategies we use to multiply whole numbers....
Take turns with your face partner and describe how we multiply and divide whole numbers.
Objective: I can multiply decimals to hundredths place.
Decimal - a number with a fraction of tenths, hundredths, etc. written after a decimal point.
Decimal point - the (.) between a whole number and fractions of tenths, hundredths, thousandths, etc.
Digit- any of the numerals 0-9, which may be part of a larger number.
24.56 x 4 . 1 = 100.696
Let’s Review
Think back to Adding and Subtracting
DecimalsStep 1- line up the decimals
Step 2- add any place holding zeros
Step 3 - add or subtract like you always do
Step 4 - bring the decimal straight down
Multiplication is much different, let’s learn how...
Rules for Multiplying Decimals
When multiplying decimals, multiply just like normal then
move decimal over to the right, then move decimal that many
place in answer to the left.
Multiplying DecimalsExample 1
Solve = 10.7 x 0.13 10.7 1 decimal place
Example 1Solve = 10.7 x 0.13
10.7x0.13
1 decimal place2 decimal places
Multiplying Decimals
Example 1Solve = 10.7 x 0.13
10.7x0.13 321
1 decimal place2 decimal places
Multiplying Decimals
Example 1Solve = 10.7 x 0.13
10.7x0.13 321 1070
1 decimal place2 decimal places
Multiplying Decimals
Example 1Solve = 10.7 x 0.13
10.7x0.13 321
+1070 1.391
1 decimal place2 decimal places
3 decimal places
Multiplying Decimals
Let’s watch how to multiply with models
http://www.slideshare.net/slideshow/embed_code/9425239
Let’s try one together...
4.56 x .83
Now you try
16.73 x 4.89
Closure
Think about what is different about multiplying whole numbers and multiplying decimals
On your slate: Write a $2 summary explaining what is different
Repeat todays objective
Independent Practice1. 45.2 x 2.3=
2. 98.01 x 7=
3. 6.6 x 4.9
4. 39.4 x 23.09=
5. 6.34 x 23 =
6. 10.6 x 15.3=
7. 99.23 x 34=
8. 7.34 x 2.34=