1. Wonderful world of Decimals 

2. What is a decimal number?
Think about money
A decimal is a part of a whole.

3. 1 dollar and 4 dimes
1.40$
Part of the whole
Whole

4. On a number line 1 4

5. It takes 10 dimes to make 1 dollar.
Look at money again.
It takes 10 dimes to make 1 dollar.
So 1 dime is 1 tenth or of the whole

6. It takes 100 pennies to make 1 dollar
A penny is one hundredth of a dollar or 0.01

7. Comparing decimal numbers
If 2 decimal numbers have different wholes
Ex.
and
The one with the larger whole is bigger.

8. Comparing decimal numbers
If the 2 numbers have the same whole but different decimal numbers.
and
The one with the larger tenth digit is bigger

9. Adding and subtracting decimals
Example :
1) Write digits with the same position under each other and line up the decimal point.
235.7
2) Add or (subtract) the numbers ignoring the decimal point.

10. Adding and subtracting decimals
3) Place the decimal point directly under the decimal of the other numbers.

11. Multiplication of decimals
1) When multiplying by a power of ten (10,100,1000…)
Move the digit one place to the LEFT for every zero
Example: 3.45 X100
=345.00

12. Multiplication with decimal numbers
Move the digit one place to the RIGHT for every zero.
=.00345

13. Multiplication For all other numbers,
1) Multiply them as if they were not decimal numbers.
35.18
X 4.7
24 626
2) Count the number of decimal places in the 2 numbers
we have 3.
3) Put the decimal place in the result so it is same as the total of the 2 numbers.

14. Word Problem
You are going shopping for groceries and you want to save as much money as possible. Here are the prices at 2 stores:
Item
Loblaws
Super C
Milk
3.59$ a litre
3.55$ a litre
Bread
4.39$
3.99$
Eggs
5.19$ for 12
4.39 $ for 12
Yogart
2.99$ for 2
3.45$ for 6
Which Grocery store would give you the best deal overall and how much would it cost?