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Good Afternoon!. Today we will be learning about Rounding Decimals numbers. Let’s warm up :. Convert the given Fraction to a Decimal valve?. 1) 2/5. 2) 2/3. Convert the given Decimal valve to a Fraction?. 3) 0.45. 4) 0.6. 5) 2.5. Review.
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Good Afternoon! Today we will be learning about Rounding Decimals numbers . Let’s warm up : Convert the given Fraction to a Decimal valve? 1) 2/5 2) 2/3 Convert the given Decimal valve to a Fraction? 3) 0.45 4) 0.6 5) 2.5 CONFIDENTIAL
Review Let’s review what we did in the last session. FRACTION : A number that names part of a whole or part of a group. ¼ means 1 part of 4 parts, where 4 parts is the whole or group. DENOMINATOR: It is the number below the bar in a fraction. NUMERATOR: It is the number above the bar in a fraction. NUMERATOR ¼ FRACTION DENOMINATOR MIXED NUMBERS : A number named by a whole number and a fraction. CONFIDENTIAL
Review Identifying, reading and writing a fraction Write a fraction to show what part of the rectangle is pink. NUMERATOR Pink part: 4 DENOMINATOR Equal parts in all: 7 So, 4 of the area is pink. 7 The fraction will be read as Four-sevenths. Write a fraction to show what part of the rectangle is blue. CONFIDENTIAL
Review We can show decimal numbers with the help of a square grid model. These grids represent 1 and 25 hundredths, 1.25, and 1 . or 1 CONFIDENTIAL
Review How do we get Fraction from Decimal? • Decimal numbers are another way to write fractions or mixed numbers. We will be using place value to do this one! • Count the decimal places of the decimal starting from the decimal point. • If there is one decimal place, place the number over 10 and reduce. • If there are two decimal places, place the number over 100 and reduce. • If there are three decimal places, place the number over 1000 and reduce. CONFIDENTIAL
Review How do we get Fraction to Decimal? • Divide the denominator (the bottom of the fraction) into the numerator (the top of the fraction). • Place a decimal point after the number inside the division "box" and attach as many zeros as necessary to handle the division. • If the quotient does not come out evenly, follow any rounding instructions. CONFIDENTIAL
Identifying Equivalent Decimals and Fractions Decimals are a type of fractional number. The decimal 0.5 represents the fraction 5/10. The decimal 0.25 represents the fraction 25/100. We know that 5/10 is equivalent to ½. Here, ½ X 5/5 is 5/10 . Again, the decimal 0.5 is equivalent to ½ or 2/4, etc. Some common Equivalent Decimals and Fractions: 0.1 and 1/10 0.2 and 1/5 0.5 and 1/2 0.25 and 1/4 0.50 and 1/2 CONFIDENTIAL
Let’s get started. Rounding decimals numbers. Estimating, or being able to guess and come close to a correct answer, is an important part of mathematics and a very handy tool for everyday life. Rounding off is a kind of estimating. Rounding decimals is very similar to rounding other numbers. The only difference is that the place value of the digits to the right of the decimal point are different. A decimal number is rounded to the whole number to which it is the nearest. A decimal number is rounded to get the estimated value of that number. CONFIDENTIAL
We can round a decimal number with the help of a number line. Round 3.4 to the nearest whole number. 3.4 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 The number 3.4 is closer to 3 than it is to 4. So, the rounded value of 3.4 is 3. CONFIDENTIAL
We can round a decimal number using place value To round off decimals: 1) Find the place value you want (the "rounding digit") and look at the digit just to the right of it. 2) If that digit is less than 5, do not change the rounding digit but drop all digits to the right of it. 3) If that digit is greater than or equal to five, add one to the rounding digit and drop all digits to the right of it. CONFIDENTIAL
Round 12.67 to the nearest tenth. STEP 1: Look at the digit in the place to the right of where you want to round. 12.67 STEP 2: If it is less than 5 round down. If it is 5 or greater than 5, round up. 12.7 Round up to 12.7. Hence, the rounded value of 12.67 to the nearest tenth is 12.7. CONFIDENTIAL
To round 75.9876 to the nearest hundredths. 1) Find the rounding digit first. 2) This is the "8". We are trying to get rid of the all the digits to the right of the 8, but the result should be as accurate as possible. 75.9876 3) Now look one digit to the right, at the digit in the thousandths place which is “7". 75.9876 4) See that 7 is more than 5, Add one to the rounding digit and change all the rest of the digits to the right of it to zero. so the number "8" is incremented to “9”. 75.99 Hence, the rounded value of 75.9876 to the nearest hundredths is 75.99 CONFIDENTIAL
To round the number 47.5434 to the nearest thousandths. 1) Find the rounding digit first. 2) This is the “3". We are trying to get rid of the all the digits to the right of the 3, but the result should be as accurate as possible. 47.5434 3) Now look one digit to the right, at the digit in the ten-thousandths place which is “4". 47.5434 4) See that 4 is less than 5, so leave the number “3" as it is, and drop the digits to the right of 3. 47.543 Hence, the rounded value of 47.5434 to the nearest hundredths is 47.543. CONFIDENTIAL
BREAK CONFIDENTIAL
GAME Click on the link below for some exciting puzzle http://http://www.thekidzpage.com/onlinejigsawpuzzles/kids-jigsaw-puzzles/12-piece-jigsaw/03-27-07-animalfriends.html CONFIDENTIAL
Assignments Round to the nearest whole number: 1) 6.78 2) 14.12 CONFIDENTIAL
3) Robby walked 3.78 miles. To the nearest mile, how much did Robby walk? CONFIDENTIAL
Round to the nearest tenths: 4) 85.73 5) 38.37 6) 7.13 CONFIDENTIAL
Round to the nearest hundredths: 7) 65.943 8) 6.727 CONFIDENTIAL
Round to the nearest thousandths: 9) 2.94374 10) 46.7276 CONFIDENTIAL
Let’s Review what we did today Estimating, or being able to guess and come close to a correct answer, is an important part of mathematics and a very handy tool for everyday life. Rounding off is a kind of estimating. We can round a decimal number with the help of a number line. Round 3.4 to the nearest whole number. 3.4 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 The number 3.4 is closer to 3 than it is to 4. So, the rounded value of 3.4 is 3. CONFIDENTIAL
Review We can round a decimal number using place value To round off decimals: 1) Find the place value you want (the "rounding digit") and look at the digit just to the right of it. 2) If that digit is less than 5, do not change the rounding digit but drop all digits to the right of it. 3) If that digit is greater than or equal to five, add one to the rounding digit and drop all digits to the right of it. CONFIDENTIAL
To round 75.9876 to the nearest hundredths. 1) Find the rounding digit first. 2) This is the "8". We are trying to get rid of the all the digits to the right of the 8, but the result should be as accurate as possible. 75.9876 3) Now look one digit to the right, at the digit in the thousandths place which is “7". 75.9876 4) See that 7 is more than 5, Add one to the rounding digit and change all the rest of the digits to the right of it to zero. so the number "8" is incremented to “9”. 75.99 Hence, the rounded value of 75.9876 to the nearest hundredths is 75.99 CONFIDENTIAL
You have done a nice job. See you in the next session. CONFIDENTIAL