Lesson Exemplar in Mathematics V

Second Quarter

I. Multiplying decimals by 10 and 100

II. Give the product of each equation.

1.) 2.9 × 10 = N 4.) 12. 93 × 10 = N

2.) 5.32 × 100 = N 5.) 12.683 × 100 = N

3.) 9.65 × 10 = N

III. Study the problem:

Mrs. Castro makes juice for her daughter’s classmates. She should add water that is 10 times the amount of juice concentrate. She has 1.75 liters of juice concentrate. How much water should she add?

To find out how much water she needs to add. Multiply 1.75 by 10.

1.75 × 10 = 17.5 (Mrs. Castro should add 17. 5)

Study these examples

5.28 × 10 = 52.8

5. 28 × 100 = 528

How do we multiply mixed decimals by 10 and 100?

Step 1: Count the number of zeroes. We move the decimal point to the right by the number of zeroes.

5.28 × 10 = N (10 has 1 zero)

5.28 × 100 = N (100 has 2 zeroes)

Step 2: Count the number of decimal place. We move the decimal point to the left by the number of zero.

5.28 × 10 = 52.8

5.28 × 100 = 528

IV. Assessment:

Find the product of the following:

1.) 9.792 × 10 = N

2.) 38.26 × 100 = N

3.) 9.516 × 100 = N

4.) 62.9 × 10 = N

5.) 83.6 × 100 = N

Lesson Exemplar in Mathematics V

Second Quarter

I. Solving word problems involving division of decimals or whole number by decimals.

II. Give the quotient of each equation.

1.) 0.98 ÷ 0.3 = N 4.) 0.25 ÷ 0.5 = N

2.) 42 ÷ 0.7 = N 5.) 450 ÷ 0.9 = N

3.) 144 ÷ 0.12 = N

III. Study the problem:

Bugoy had a stick 0.5 meter long. He divided it into 0.1 meter long. How many of these pieces does he have?

To find out the number of 0.1 meter stick he has, divide 0.5 by 0.

0.5 ÷ 0.1 = 5 (Are there five 0.1 meter in 0.5 meter stick?) Prove!

How are we going to solve the problem involving division of decimals or whole number by decimals?

Follow the steps in solving problem.

Step 1: Understand the problem- Number of 0.1 meter in 0.5 meter stick

Step2: Choose a strategy- Visual Illustration

Step 3: Change decimal numbers (the divisor) to whole number by moving the decimal places to the left.

0.5 ÷ 0.1 = n (0.1 is the divisor, moving 1 decimal place makes it 1)

0.5 ÷ 1 = n

0.5 meter

0.1 meter

Step 4: Move the decimal point of the Dividend to the left according to how many decimal places the divisor is moved.

Since the divisor has moved 1 decimal place to make it whole number, then:

0.5 ÷ 1 = n (move one decimal place in the dividend)

5 ÷ 1 = 5

Step 5: Check the answer using inverse operation ( Multiplication)

5 × 0.1 = 0.5

IV. Assessment: Analyze and Solve the problems.

1. Ame has 15.73 meters of ribbon. If she cut it into three equal pieces, what is the measurement of each piece?

2. Jackie has 2.5 liters of water. How many times will she has to drink if she consumes 0.5 liter from time to time?

3. From station A to Station B, Goms Jogged a total of 15.75 kilometre in a week. About how many kilometres did he jog every day?