NOTES Multiplying Decimals MULTIPLYING DECIMALS: 1 st MULTIPLY AS NORMAL 2 nd Count the number of digits behind the decimal in the factors (in the problem)

Slides:

Advertisements

Similar presentations

SOLUTION EXAMPLE 6 Standardized Test Practice The dimensions of a rectangle are x + 3 and x + 2. Which expression represents the area of the rectangle.

Advertisements

EXAMPLE 1 Standardized Test Practice SOLUTION Substitute several values of h into the equation C = h and solve for C.Then identify the table that.

EXAMPLE 4 Solve a multi-step problem

Do Now: Pass out calculators. Complete EOC Review Week # 17. Have your homework out ready to check.

EXAMPLE 2 Use a ratio to find a dimension SOLUTION Painting You are planning to paint a mural on a rectangular wall. You know that the perimeter of the.

Use the cross products property EXAMPLE 1 Write original proportion = x 6 Solve the proportion =. 8 x 6 15 Cross products property Simplify. 120.

EXAMPLE 1 Finding Perimeter and Area SOLUTION Find the perimeter. P = 2l + 2w Write formula. = 2 ( 8 ) + 2( 5 ) Substitute. = 26 Multiply, then add. Find.

L E S S O N Multiplying Decimals 0.7

Multiplying Decimals. Multiplying Decimals Notes Multiply as usual, ignoring the decimal points. Count how many total digits are to the right of the decimal.

Write decimal as percent. Divide each side by 136. Substitute 51 for a and 136 for b. Write percent equation. Find a percent using the percent equation.

EXAMPLE 1 Multiplying Decimals decimal places + 2 decimal places 4 decimal places.

Solve for unknown measures

Divide each side by 2. Write original equation. Write 3x + 2y = 8 so that y is a function of x. EXAMPLE 2 Rewrite an equation Subtract 3x from each side.

Connections to algebra Algebra Chapter 1. Entry Task 09/12/2012 Evaluate the Expression using your brain. 1) 2*1= 2) 2*2= 3) 2*3= 4) 2*4= 5) 2*5= 6) 2*6=

Calculations with Significant Figures

SOLUTION EXAMPLE 2 Find the greatest common monomial factor Factor out the greatest common monomial factor. a. 12x + 42y a.a. The GCF of 12 and 42 is 6.

EXAMPLE 1 Evaluate powers a. (–5) 4 b. –5 4 = (–5) (–5) (–5) (–5)= 625 = –( )= –625.

Warm-Up #2 Simplify the expression. 2. –6(m – 9) + 14m – 20

OBJ: To use a problem solving plan to solve problems.

Standardized Test Practice EXAMPLE 3 Use the formula for the area of a rectangle, A = lw, with l = 18 inches and w = 11 inches. SOLUTION.

Order of Operations Also known to as PEMDAS. EXAMPLE 1 Following Order of Operations Music You buy a used guitar for $50. You then pay $10 for each of.

Find the product. 0.4” (height) Warm-Up Exercises () 8 – m () 9m – ANSWER m 2m 2 17m72 + –z 2z 2 4z4z60 –– ANSWER y 2y – ANSWER d 2d 2 18d+81+ ANSWER.

EXAMPLE 3 Use the Area of a Sector Theorem Use the diagram to find the area of V. SOLUTION Area of sector TVU = Area of V m TU 360 ° Write formula for.

EXAMPLE 1 Find the volume of a solid Find the volume of the solid. V = Bh 1 3 = 36 m 3 a.a. = ( 4 6)(9)

EXAMPLE 2 Rationalize denominators of fractions Simplify

Over Lesson 10–1 A.A B.B C.C D.D 5-Minute Check 4 The area of a square is 200 cm 2. Estimate the length of a side of the square.

Warm-Up Exercises 1. Simplify –2 (9a – b). ANSWER –18a + 2b ANSWER r3s4r3s4 2. Simplify r 2 s rs 3.

Warm Up Lesson Presentation Lesson Quiz

Write the radical expression in simplest form.

Equivalent ANSWER 2, 3 ANSWER Prerequisite Skills VOCABULARY CHECK Copy and complete the statement In the fraction, is the numerator and is the.

Evaluating Algebraic Expressions 3-7 Solving Inequalities by Multiplying and Dividing Warm Up Warm Up California Standards California Standards Lesson.

Divide. Evaluate power – 3 = – 3 EXAMPLE – 3 = 3 2 – – 3 = 6 – 3 Multiply. Evaluate expressions Multiply and divide from.

EXAMPLE 2 Rewrite a formula with three variables SOLUTION Solve the formula for w. STEP 1 P = 2l + 2w P – 2l = 2w P – 2l 2 = w Write perimeter formula.

Graph and on a number line. Then copy and complete the statement with, or Example 2 Comparing Real Numbers 1 ? = SOLUTION Use a calculator.

EXAMPLE 2 Use a ratio to find a dimension SOLUTION Painting You are planning to paint a mural on a rectangular wall. You know that the perimeter of the.

Read a problem and make a plan EXAMPLE 1 Running You run in a city where the short blocks on north-south streets are 0.1 mile long. The long blocks on.

12/12/ : Using Formulas Expectation: You will be able to use the formulas for area and perimeter of a rectangle to calculate (with correct units)

3x 2 4x 6 Write an expression that represents the area of the rectangle. Example 1 Steps for Exponent Applications 1) Write the appropriate formula 2)

I can multiply decimals

Example 3 In parts of New York City, the blocks between streets are called short blocks. There are 20 short blocks per mile. Blocks between avenues are.

SECONDARY ONE 6.1a Using Substitution to Solve a System.

Math 8 - Unit 1 Square Roots and the Pythagorean Theorem A square number or perfect square is any number that is a product that forms when we multiply.

9.2 Multiply Polynomials I can…multiply polynomials

Multiplying Decimals NS3

Which list of numbers is ordered from least to greatest? 10 –3, , 1, 10, , 1, 10, 10 2, 10 – , 10 –3, 1, 10, , 10 –3,

SOLUTION EXAMPLE 6 Standardized Test Practice The dimensions of a rectangle are x + 3 and x + 2. Which expression represents the area of the rectangle.

Location of Exponent An An exponent is the small number high and to the right of a regular or base number. 3 4 Base Exponent.

SOLUTION EXAMPLE 2 Find the greatest common monomial factor Factor out the greatest common monomial factor. a. 12x + 42y a.a. The GCF of 12 and 42 is 6.

Bell Work: Simplify 4/5 + 1/2. Answer: 4/5 + ½ = 13/10 or 1 3/10.

EXAMPLE Ordering Real Numbers Order the numbers 0.47, 0.474, 0.47, and 0.23 from least to greatest. SOLUTION STEP 1 Write each decimal out to six.

Warm-Up Exercises EXAMPLE 1 Standardized Test Practice What are the solutions of 3x 2 + 5x = 8? –1 and – A 8 3 B –1 and 8 3 C 1 and – 8 3 D 1 and 8 3 SOLUTION.

1. Simplify –2 (9a – b). ANSWER –18a + 2b 2. Simplify r2s rs3. ANSWER

How do you calculate the area of squares and rectangles?

Multiplying Decimals.

Do-Now Evaluate the expression when x = –3. –5 ANSWER 1. 3x

Finding Perimeter and Area

L E S S O N Multiplying Decimals 0.7

Homework Assistance Guide

Rewrite a formula with three variables

Ratio & Proportions Practice

SOLVING QUADRATIC EQUATIONS USING THE FORMULA

Multiplying Decimals.

The Derivative as a Function

Multiply Polynomials Warm Up Lesson Presentation Lesson Quiz.

“Day A” January 9, :51 -8:51 Math 8:53 -9:53 Science 9:55-10:55

It’s the middle of the week!

Substitution 3..

Multiplying Decimals Chapter 4.

Presentation transcript:

NOTES Multiplying Decimals MULTIPLYING DECIMALS: 1 st MULTIPLY AS NORMAL 2 nd Count the number of digits behind the decimal in the factors (in the problem) 3 rd That is how many numbers should be behind the decimal in your answer Name: ___________Date: __________ Math ___ hrMC2 pg 65 section 2.3

EXAMPLE 1 Multiplying Decimals decimal places + 2 decimal places 4 decimal places.

EXAMPLE 2 a.a decimal places ANSWER = decimal places Multiplying Decimals.

EXAMPLE 2 b.b decimal places 5 decimal places ANSWER = decimal places 7638 Multiplying Decimals

EXAMPLE 2 GUIDED PRACTICE for Examples 1 and 2 I am giving you the digits that are in your answer. PLACE THE DECIMAL = ANSWER * 0.21 = ANSWER * 1.6 = ANSWER

EXAMPLE 3 Finding Area Finding Area with Decimals Central Park Central Park, in New York City, is a rectangular park about 2. 5 miles long and about 0. 5 mile wide. What is the area of Central Park? SOLUTION A = l * w = 2.5 * 0.5 = 1.25 Write formula Write formula for area of a rectangle. Substitute Substitute 2.5 for l and 0.5 for w. Solve! Solve! Multiply. The area of Central Park is about square miles. ANSWER L= 2.5 mi W= 0.5 mi

EXAMPLE 3 GUIDED PRACTICE for Example 3 Find the area of the rectangle. 7. ANSWER in ANSWER cm 2 A = L * W A = 9.42 * 2 A = L * W A = 8.4 * 4.3 A = A =

EXAMPLE 3 GUIDED PRACTICE EXAMPLE 4 Standardized Test Practice STEP 1 Calculate the least possible cost by using $.25 as the price for all of the fruits and vegetables. C = = $ 3.60 SOLUTION

EXAMPLE 3 GUIDED PRACTICE EXAMPLE 4 STEP 2 Calculate the greatest possible cost by using $2.10 as the price for all of the fruits and vegetables. C = = $ ANSWER The least cost for food is $3. 60 and the greatest cost is $ The correct answer is C. A B C D Standardized Test Practice

EXAMPLE 3 GUIDED PRACTICE EXAMPLE 3 GUIDED PRACTICE for Example 4 ANSWER $4.20 to $35.28 In Example 4, suppose you buy 16.8 pounds of fruits and vegetables. What is the range of the amount you might spend? What If? 9.

EXAMPLE 2 GUIDED PRACTICE m Evaluate the expression when m = 3.26 and n = ANSWER n ANSWER 6. mn ANSWER for Examples 1 and 2

MULTIPLYING DECIMALS: 1 st MULTIPLY AS NORMAL 2 nd Count the number of digits behind the decimal in the factors (numbers in the problem) 3 rd That is how many numbers should be behind the decimal in your answer Name: ___________Date: __________ Math ___ hrMC2 pg 65 (2-7all, 9-20 evens, all, evens)