Comparing and Ordering Decimals 1

Comparing and Ordering Decimals 1 - Transcript

Comparing and Ordering Comparing and Ordering Decimals
When Will I Ever Do That

McDonald s Menu Mc I m Lovin It


Double Cheeseburger 99 Big Mac Value Meal 4 79 Chicken McNuggetts Meal 3 80 Small Drink 99 McFlurry 1 97 Salad 4 80 2 Cheeseburger Meal 3 70 Ice Cream Cone 87

Order Up Order Up Least Expensive to Most Expensive


Ice Cream Cone 87 Double Cheeseburger 99 Small Soft Drink 99 McFlurry 1 97 2 Cheeseburger Meal 3 70 Chicken McNuggetts Meal 3 80 Big Mac Value Meal 4 79 Chicken Salad 4 80

What Do I Mean Compare What Do I Mean Compare Decimals


When we compare we use terms such as




Comparing decimals is similar to comparing whole numbers


Less than Greater than Equal to 45 47 150 105



When we compare decimals we use place value or a number line

Place Value Place Value
1 000 100 10 1 0 1 0 01 0 00 0 000 1 1

Half pipe Results


1

Sara Danny Ross

42 1 42 5 42 0

Compare Sara s score with Danny s score
Line Up Decimal Points


Sara 42 1 Danny 42 5

1

Bethany 40 7 Jacob 46 1

Start at the left and find the first place where the digits differ Compare the digits 1 5 42 1 42 5 This means Sara s score was lower than Danny s score

Let s Try Using A Number Let s Try Using A Number Line
Sara Danny Ross Bethany Jacob 42 1 42 5 42 0 40 7 46 1

42 0 42 1

42 5

Numbers to the right are greater than numbers to the left Since 42 5 is to the right of 42 1 we have 42 5 42 1

Equivalent Decimals Equivalent Decimals


Decimals that name the same number are called equivalent decimals 0 60 and 0 6 Are these the same



0 60



0 6

Annexing Zeros Annexing Zeros






This means placing a zero to the right of the last digit in a decimal 0 6 0 60 Although we added a zero the value of the decimal did not change Annexing or adding zeros is useful when ordering a group of decimals

Ordering Decimals Ordering Decimals




We can order decimals from least to greatest or we can order from greatest to least Let s try an example Order 15 14 95 15 8 and 15 01 from least to greatest



15 14 95 15 8 15 01
First line up the decimal points 15 14 95 15 8 15 01


15 14 95 15 8 15 01 15 14 95 15 8 15 01
Next annex zeros so that each number has the same number of decimal places 15 00 14 95 15 80 15 01


15 14 95 15 8 15 01 15 14 95 15 8 15 01
Finally use place value to compare the decimals Always start from the left 15 00 14 95 15 80 15 01 14 95 15 15 01 15 8


One More Example One More Example


Order these numbers from greatest to least 35 06 35 7 35 5 35 849