# Rounding Decimals Review and Multiplying Decimals

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Rounding Decimals Review and Multiplying Decimals

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Rounding Review Decimals are read as “and” ___ , ___ ___ ___ ___ ___ ___ ___ Thousandths Thousands Ones Hundredths Hundreds Tens Tenths Ten Thousandths Read as 518 and 21 hundredths copyright©amberpasillas2010

Rounding Review Find the number. Circle it. Look next door. 4 or less just ignore. 5 or more add one more. Example: Round 5368 to nearest hundreds. Circle the 3 in the hundreds place. Look next door at the 6. It is 5 or more so add 1 more to the hundreds place. 5368 rounds to 5400 copyright©amberpasillas2010

Rounding Review Round to the nearest tenths Round to the nearest hundredths 2.876 2.9 31.70 copyright©amberpasillas2010

Rounding Review Round to the nearest tenths Round to the nearest hundredths 3.478 3.5 22.60 copyright©amberpasillas2010

Multiplying Decimals Steps for Multiplying Decimals Step 1: Write the problem vertically. Step 2: Ignore the decimal point(s) and multiply. Step 3: Determine where the decimal point goes in the product. Place the decimal point in the answer by counting how many places the decimal point has moved. copyright©amberpasillas2010

Multiplying Decimals Multiply 3 x 0.14 = 0.42 0.14 3 x 0.14 copyright©amberpasillas2010

Multiplying Decimals Multiply 3 x 0.14 1 Step 1: Write the problem vertically 0.14 x Step 2: Ignore the decimal points and multiply 4 2 Step 3: Determine where the decimal point goes in the product. 0.42 The decimal moves two places to the left copyright©amberpasillas2010

Multiplying Decimals Multiply 5 x 0.18 = 0.90 5 x 0.18 0.18 copyright©amberpasillas2010

Multiplying Decimals Multiply 5 x 0.18 4 Step 1: Write the problem vertically 0.18 x Step 2: Ignore the decimal points and multiply 9 Step 3: Determine where the decimal point goes in the product. 0.90 The decimal moves two places to the left copyright©amberpasillas2010

Multiplying Decimals Multiply 0.2 x 0.6 = 0.2 x 0.6 0.6 0.2 copyright©amberpasillas2010

Multiplying Decimals Multiply 0.2 x 0.6 = 0.2 x 0.6 0.6 0.2 = 0.12 copyright©amberpasillas2010

Multiplying Decimals Multiply 0.2 x 0.6 Step 1: Write the problem vertically 0.2 x 0.6 Step 2: Ignore the decimal points and multiply 1 2 Step 3: Determine where the decimal point goes in the product. 0. 12 The decimal moves two places to the left copyright©amberpasillas2010

Multiplying Decimals Multiply 0.4 x 0.7 = 0.7 0.4 0.4 x 0.7 copyright©amberpasillas2010

Multiplying Decimals Multiply 0.4 x 0.7 Step 1: Write the problem vertically 0.4 x 0.7 Step 2: Ignore the decimal points and multiply 2 8 Step 3: Determine where the decimal point goes in the product. 0. 28 The decimal moves two places to the left copyright©amberpasillas2010

Multiplying Decimals 200 Move the decimal two places to the left in your answer. x . 25 1 + 4 . 5000 copyright©amberpasillas2010

Multiplying Decimals HOW MANY DECIMAL PLACES? 1) 3.1(0.28) 3.1 1 decimal place 2 decimal places 0.868 1 + 2 = 3 decimal places 2) (0.4)(2.53) 0.4 1 decimal place  2.53 2 decimal places 1.012 1 + 2 = 3 decimal places copyright©amberpasillas2010

Multiplying Decimals 1 2 1 1) 1 0.16 x 30 2) 70 x 1.2 3) 0.0048 x 32 1 4 1 9 6 4 8 + 7 1 4 4 4 8 8 4 1 5 3 6 copyright©amberpasillas2010

Evaluate The Power An exponent tells how many times a number is multiplied by itself. 4 3 Exponent Base 4 3 is written as 3 • 3 • 3 • 3 = 81 This exponent is read three to the fourth power. copyright©amberpasillas2010

Evaluate The Power Evaluate (0.2)2 This means (0.2)(0.2) 0.2 x 0.2 4 0. 04 The decimal goes moves two places to the left copyright©amberpasillas2010

Calculate Area With Decimals
Area = base x height 0.58 in. Multiply 4 x 0.58 4 in. 3 2 The decimal moves two places to the left. 0.58 x Area is square units! 2 3 2 2.32 in2 copyright©amberpasillas2010

Multiplying Decimals Multiply 0.4 x 0.14 0.056
#5 Multiply 0.4 x 0.14 1 0.14 x Step 1: Write the problem vertically Step 2: Ignore the decimal points and multiply 5 6 Step 3: Determine where the decimal point goes in the product. 0.056 The decimal moves 3 places to the left.

The decimal moves two places to the left.
Evaluate The Power #6 Evaluate (0.5)2 This means (0.5)(0.5) 2 0.5 x 0.5 The decimal moves two places to the left. 2 5 0. 25

Calculate Area With Decimals
# 7 Calculate Area With Decimals The Area (A) is the number of square units needed to cover a figure. 0.98 in Area = base x height 2 in. Multiply 2 x 0.98 1 1 The decimal moves two places to the left. 0.98 x 1 9 6 Area is square units! 1.96 in2