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Example 3-3f Objective Divide decimals by whole numbers

Example 3-3f Review Vocabulary Quotient The solution in division

Lesson 3 Contents Example 1Divide a Decimal by a 1-Digit Number Example 2Divide a Decimal by a 2-Digit Number Example 3Round a Quotient

Example 3-1a Find 1/3 Write problem using the division house Put the first number in the house Put the second number outside the house How many times does 3 go into 4? Multiply 3  1 and place under the 4 Subtract Bring down the 5

Example 3-1a Find 1/3 How many times does 3 go into 15? Multiply 3  5 and place under the 15 Subtract Bring down the 9 How many times does 3 go into 9? Multiply 3  3 and place under the 9 Subtract Put decimal in answer directly above decimal in house Answer: 15.3

Example 3-1b Answer: 12.7 Find 1/3

Example 3-2a Find 2/3 Write problem using the division house Put the first number in the house Put the second number outside the house How many times does 22 go into 8? 22 will not go into 8 How many times does 22 go into 86?

Example 3-2a Find 2/3 How many times does 22 go into 209? Multiply 22  3 and place under the 86 Subtract Bring down the 9 Subtract Multiply 22  9 and place under the 209 Annex a 0 and bring down

Example 3-2a Find 2/3 How many times does 22 go into 110? Multiply 22  5 and place under the 110 Subtract Put decimal in answer directly above decimal in house Answer: 0.395

Example 3-2b Answer: 0.36 Find 2/3

Example 3-3a During a science experiment, Nita measured the mass of four unknown samples. Her data table is shown below. What is the mean mass of the four samples? Sample g Sample g Sample g Sample g 3/3 Remember: To find the mean, add the data, then divide by how many pieces of data Mean = A + B + C + D There are 4 pieces of data 4

Example 3-3a Sample g Sample g Sample g Sample g 3/3 Mean = A + B + C + D Replace A with Sample 1 of Mean = Replace B with Sample 2 of Replace C with Sample 3 of Replace D with Sample 4 of Bring down the 4 4

Example 3-3a 3/3 Mean = A + B + C + D 4 Mean = Follow order of operation 4 PEMDAS Fraction bar considered an enclosure Add the numerator Mean = Bring down the 4 4 Write division using the house Put numerator in house Put denominator outside the house 4

Example 3-3a 3/3 Mean = How many times does 4 go into 2? 4 will not go into 2 How many times does 4 go into 24? 6 Multiply 4  6 and place under the Subtract Bring down the 4 4

Example 3-3a 3/3 Mean = How many times does 4 go into 4? 6 Multiply 4  1 and place under the 4 24 Subtract Bring down the How many times does 4 go into 4? 1 Multiply 4  1 and place under the 4 4 Subtract Put decimal in answer directly above decimal in house. Answer: Mean = 6.11 grams

Example 3-3e GRID-IN TEST ITEM The birth weights of four babies born at City Hospital last Friday are given in pounds. What is the mean birth weight? Baby lb Baby lb Baby lb Baby lb Answer: Mean = 7.47 lb * 3/3

End of Lesson 3 Assignment Lesson 4:3Dividing Decimals All by Whole Numbers