Compare And Order Rational Numbers

Compare And Order Rational Numbers ??

Participant Objective The purpose of the lesson is to determine participants understanding of reading, comparing, and ordering of fractions, decimals and percents.

Benchmark MA.6.A.5.3 Estimate the results of computations with fractions, decimals, and percents and judge the reasonableness of the results

Reasonableness Defined as: • having good sense and sound judgment • being prudent and sensible • being plausible or acceptable

Reasonableness examples

Proper Fractions A proper fraction is a fraction that is less than 1 and greater than zero.

Decimals A decimal is the representation of a real number using the base 10 and decimal notation, such as 201.4, 3.89, or 0.0006.

Decimals vs Fractions A "decimal" is a fraction whose denominator we do not write but which we understand to be a power of ten. For example, 0.4 is read as four tenths or 4/10 0.74 is read as seventy four hundredths or 74/100

Percents A percent is a way of expressing a number as a fraction of 100. Per cent means "per hundred”. For example, 20% is read as twenty percent or 20/100 3% is read as three percent or 3/100

Fractions, Decimals, Percents All represent a part of a whole. • A fraction is based on the number into which the whole is divided (the denominator). The numerator (the top) is the PART, the denominator (the bottom) is the WHOLE. • A decimal is based on the number in terms of tenths, hundredths, thousandths, etc. • A percent is based on the number in terms of 100.

Judging Reasonableness Example #1

Benchmark MA.6.A.5.2 Compare and order fractions, decimals, and percents, including finding their approximate location on a number line.

What are rational numbers? Rational numbers are parts of a whole. They can be expressed as a fraction (1/4), a decimal (0.25) or a percent (25%). Rational numbers can be plotted on a number line.

Egyptian Fractions • The ancient Egyptians only used fractions of the form 1/n . • All fractions had to be represented as a sum of such unit fractions. • This makes it easier to compare fractions.

Egyptian Fractions How it worked: Egyptians had a notation for 1/2 and 1/3 and 1/4 and so on (these were called reciprocals or unit fractions since they are 1/n for some number n).

Egyptian Fractions How did they write 2/5 or 3/4? They were able to write any fraction as a sum of unit fractions 2/5 = 1/5 + 1/5 3/4 = 1/2 + 1/4

Egyptian Fractions So suppose Faith has 5 loaves of bread to share among the 8 people.

Egyptian Fractions Faith sees that she can give each person half a loaf, with one loaf left over. 5 6 1 2 3 4 7 8 ?

Egyptian Fractions Faith takes the one loaf that is left and divides it into 8 pieces, so each person gets half a loaf and an eighth of a loaf. 1 2 3 4 5 7 6 8

Egyptian Fractions Using Egyptian Fractions we see that 5/8 = 1/2 + 1/8

Egyptian Fractions Suppose Faith had 3 loaves to share between 4 people. How would she do it? 1 2 3 4 1 2 3 4 each person gets half a loaf and a fourth of a loaf. 1/2 + 1/4 = 3/4

Egyptian Fractions What if she had 2 loaves to share among 5 people? 1 1 2 2 4 3 3 4 5 5 each person gets a fifth a loaf and a fifth of a loaf. 1/5 + 1/5 = 2/5

Egyptian Fractions What if she had 4 loaves to share between 5 people? 2 3 4 1 5 ? ? each person gets half a loaf

Egyptian Fractions What if she had 4 loaves to share between 5 people? There is ½ of a loaf and 1 loaf left. 1 2 3 4 5 ? each person gets a fourth a loaf in addition to their a half of a loaf. 1/2 + 1/4 + ?

Egyptian Fractions What if she had 4 loaves to share between 5 people? There is 1/5 of a loaf left. 1 2 3 4 5 each person gets a fifth of the fourth that was left in addition to their a half of a loaf and a quarter of a loaf. 1/2 + 1/4 + 1/20 = 16/20

Using Egyptian Fractions to Compare Fractions Which is larger: 3/4 or 4/5?

Using Egyptian Fractions to Compare Fractions Using Egyptian fractions we write each as a sum of unit fractions: 3/4 = 2/4 + 1/4 = 1/2 + 1/4 4/5 = 1/2 + 3/10 = 1/2 + 6/20 = 1/2 + 1/20 + 5/20 = 1/2 + 1/4 + 1/20

Using Egyptian Fractions to Compare Fractions 3/4 = 1/2 + 1/4 4/5 = 1/2 + 1/4 + 1/20 4/5 is the larger than 3/4 by exactly 1/20

Comparing Fractions using Decimals Convert the fractions to decimals: 3/4 =75/100 or 0.75 4/5 = 80/100 or 0.80 80 (hundredths) is bigger than 75 (hundredths) therefore 4/5 is bigger than 3/4

Ordering Rational Numbers One way to order rational numbers is graphing them on a number line. On a number line, the rational number to the right of another rational number is greater. least greatest

Ordering Rational Numbers A second method is to convert all rational numbers to decimals. Place the following numbers in order largest to smallest: 1.112, 0.234, 1.056, 0.45 Place zero in empty spots 0

Ordering Decimal Numbers Place the following numbers in order largest to smallest: 1.112, 0.234, 1.056, 0.45 largest smallest

Ordering Rational Numbers Besides using number line, and decimals, you can use the common denominator method. Convert all rational numbers to fractions with common denominators. Place the following numbers in order from smallest to largest: 2/5 , 11/2 , 3/4 , 15/6

Ordering Rational Numbers Place the following numbers in order from smallest to largest: 2/5 , 11/2 , 3/4 , 15/6 2/5 = 24/60 11/2 = 3/2 = 90/60 3/4 = 45/60 15/6 = 11/6 = 110/60 smallest largest

Ordering Rational Numbers The order from smallest to largest is 2/5 , 3/4 , 11/2 , 15/6 2/5 = 24/60 11/2 = 3/2 = 90/60 3/4 = 45/60 15/6 = 11/6 = 110/60 smallest largest

Guided Practice #1 Which is the greater number, 23% or 2.5 Percent means per hundred. So, 23% is the same as 23/100 or 0 .23 0 .23 is smaller than 2.5 2.5 > 23%

Guided Practice #2 Graph this set of numbers on a number line. What is the order of the set of numbers from least to greatest? -1.5, 2, 21/2 , -2 5/6 , 1.4, 25%

Guided Practice #2 Step 1: Draw a number line from -3 to 3 with equal intervals. Step 2: Plot each point asked for in the problem: -1.5, 2, 21/2 , -2 5/6 , 1.4, 25% 2 21/2 -25/6 -1.5 25% 1.4

Guided Practice #2 Step 3: Use the points plotted on the number line to write the numbers in order from least to greatest. -25/6 , -1.5, 25%, 1.4, 2, 21/2 2 21/2 -25/6 -1.5 25% 1.4

Directions • two teams with a set of plates. • Each team member should have a plate. • This is a silent game, if a student talks during play, a point will be deducted from the team’s score. • Show the first problem.

Directions Continue • Once the problem is uncovered, the team members with the appropriate plates should arrange themselves at the front of the class to represent the number/problem displayed from the transparency. • The students have 30 seconds to form the number/problem at the front of the class. After 30 seconds, each team is given a point for a correct answer.

7. An additional point is given to the first team to “present” the correct answer. 8. Play continues until all of the numbers/problems have been displayed. 9. The winning team is the one with the most points at the end of the game.

Presentation Numbers 1. five thousand, two and one tenth 2. Seven hundred twenty-three and eight hundredths 3. Eighty and four thousandths 4. Nine thousandths 5. One and fifty-three hundredths 6. Two hundred one thousand, thirty-six

Presentation numbers continue 7. Fifteen and two tenths. 8. One hundred twenty thousand, three hundred seven and four tenths. 9. Four hundred twenty-five thousand, three hundred seventeen and eight thousandths. 10.one hundred forty-six thousand, three hundred ninety-seven

Guided Practice……….. Place the following numbers in order from greatest to least. 0.75, 0.615, 0.58, 0.195 1. Line-up numbers and add zero(s) 0.750 0.615 0.580 0.195

2. Look at number in the tenths place, all the numbers are different, so arrange that number in order from greatest to least. .615 ,.195, .580, .750, than reorder all .750 .615 .580 .195

How do you compare and order non-negative rational numbers? To answer this question click on the webpage. Do the practice exercise of your choice, complete exercise according to web directions. http://www.aaamath.com

Conclusion • Understanding place value can help you compare and order numbers. • Start at the far left place value of the numbers, adding zero(s) as place holders when the numbers don’t have the same number of place values. • Compare the digit of each place value where the digits are different. • The way those digits compare is the way the whole numbers compare. • Use > (greater than), < (less than), or = (equal to) when comparing numbers.

Compare And Order Rational Numbers