DECIMALS Rounding Decimals Review and Multiplying Decimals copyrightamberpasillas
DECIMALS Rounding Decimals Review and Multiplying Decimals copyright©amberpasillas 2010
Rounding Review Decimals are read as “and” copyright©amberpasillas 2010 Ten Thousandths Read as 518 and 21 hundredths Thousandths Hundredths Ones Tens Hundreds Thousands 2 1 ___ ___ Tenths 5 1 8 ___ , ___ ___
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©amberpasillas 2010
Rounding Review Round to the nearest tenths Round to the nearest hundredths 2. 876 2. 9 31. 6999 31. 70 copyright©amberpasillas 2010
Rounding Review Round to the nearest tenths Round to the nearest hundredths 3. 478 3. 5 22. 5972 22. 60 copyright©amberpasillas 2010
Multiplying Decimals Steps for Multiplying Decimals Step 1: Step 2: Write the problem vertically. Ignore the decimal point(s) and multiply. Determine where the decimal point goes in the product. Step 3: Place the decimal point in the answer by counting how many places the decimal point has moved. copyright©amberpasillas 2010
Multiplying Decimals Multiply 3 x 0. 14 = 0. 14 3 x 0. 14 copyright©amberpasillas 2010 0. 42
Multiplying Decimals Multiply 3 x 0. 14 x 1 0. 14 Step 1: Write the problem vertically 3 0 42 Step 2: Ignore the decimal points and multiply 0. 42 Step 3: Determine where the decimal point goes in the product. The decimal moves two places to the left copyright©amberpasillas 2010
Multiplying Decimals Multiply 5 x 0. 18 = 0. 18 5 x 0. 18 copyright©amberpasillas 2010 0. 90
Multiplying Decimals Multiply 5 x 0. 18 x 4 0. 18 Step 1: Write the problem vertically 5 0 90 Step 2: Ignore the decimal points and multiply 0. 90 Step 3: Determine where the decimal point goes in the product. The decimal moves two places to the left copyright©amberpasillas 2010
Multiplying Decimals Multiply 0. 2 x 0. 6 = 0. 2 0. 6 copyright©amberpasillas 2010 0. 2
Multiplying Decimals Multiply 0. 2 x 0. 6 = 0. 2 0. 6 copyright©amberpasillas 2010 0. 2 x 0. 6
Multiplying Decimals Multiply 0. 2 x 0. 6 = 0. 2 0. 6 copyright©amberpasillas 2010 0. 2 x 0. 6 = 0. 12
Multiplying Decimals Multiply 0. 2 x 0. 6 0. 2 Step 1: Write the problem vertically x 0. 6 0 12 Step 2: Ignore the decimal points and multiply 0. 12 Step 3: Determine where the decimal point goes in the product. The decimal moves two places to the left copyright©amberpasillas 2010
Multiplying Decimals Multiply 0. 4 x 0. 7 = 0. 4 0. 7 copyright©amberpasillas 2010 0. 4
Multiplying Decimals Multiply 0. 4 x 0. 7 = 0. 4 0. 7 copyright©amberpasillas 2010 0. 4 x 0. 7
Multiplying Decimals Multiply 0. 4 x 0. 7 = 0. 4 0. 7 copyright©amberpasillas 2010 0. 28
Multiplying Decimals Multiply 0. 4 x 0. 7 0. 4 Step 1: Write the problem vertically x 0. 7 0 28 Step 2: Ignore the decimal points and multiply 0. 28 Step 3: Determine where the decimal point goes in the product. The decimal moves two places to the left copyright©amberpasillas 2010
Multiplying Decimals 200 x. 25 0 100 + 4 000 5000 . Move the decimal two places to the left in your answer. copyright©amberpasillas 2010
Multiplying Decimals HOW MANY DECIMAL PLACES? 1) 3. 1(0. 28) 3. 1 0. 28 0. 868 1 decimal place 2 decimal places 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©amberpasillas 2010
Multiplying Decimals 1 1) 0. 16 x 30 0 00 480 2) 70 x 1. 2 1 40 +7 0 0 840 copyright©amberpasillas 2010 21 1 3) 0. 0048 x 32 010 9 6 01 440 01 536
Evaluate The Power An exponent tells how many times a number is multiplied by itself. 4 Base 4 3 Exponent 3 is written as 3 • 3 • 3 = 81 This exponent is read three to the fourth power. copyright©amberpasillas 2010
Evaluate The Power Evaluate (0. 2) 2 This means (0. 2) 0. 2 x 0. 2 0 04 0. 04 The decimal goes moves two places to the left copyright©amberpasillas 2010
Calculate Area With Decimals 0. 58 in. Area = base x height 4 in. The decimal moves two places to the left. Multiply 4 x 0. 58 2 3 0. 58 x 4 2 32 2. 32 in copyright©amberpasillas 2010 2 Area is square units!
THE END!!! Take out your study guide copyright©amberpasillas 2010
#5 Multiplying Decimals 1 0. 14 x 0. 4 Multiply 0. 4 x 0. 14 Step 1: Write the problem vertically 0 0 56 Step 2: Ignore the decimal points and multiply 0. 056 Step 3: Determine where the decimal point goes in the product. The decimal moves 3 places to the left. copyright©amberpasillas 2010
#6 Evaluate The Power Evaluate (0. 5) 2 This means (0. 5) The decimal moves two places to the left. 2 0. 5 x 0. 5 0 25 0. 25 copyright©amberpasillas 2010
#7 The Area (A) is the number of square units needed to cover a figure. Area = base x height 0. 98 in 2 in. The decimal moves two places to the left. Multiply 2 x 0. 98 1 1 0. 98 x 2 1 96 1. 96 in copyright©amberpasillas 2010 2 Area is square units!
- Slides: 28