Unit 2 Real World Problems and Estimation

Key Words Sum- Add Difference- Subtract Product- Multiply Quotient- Divide

Solving Word Problems Analyze the problem Decide what it is asking Pick out the important information Decide which operation you need to use Find the solution Check your answer to see if it sounds reasonable

Example 1 Jake is laying carpet in three rooms of his house. The dimensions of the room are 12 feet by 10 feet, 16 feet by 15 feet and 10 feet by 9 feet. How many square feet of carpet will be needed?

Example 1 Jake is laying carpet in three rooms of his house. The dimensions of the room are 12 feet by 10 feet, 16 feet by 15 feet and 10 feet by 9 feet. How many square feet of carpet will be needed? Strategy: Find the area of each room.

Example 1 Jake is laying carpet in three rooms of his house. The dimensions of the room are 12 feet by 10 feet, 16 feet by 15 feet and 10 feet by 9 feet. How many square feet of carpet will be needed? Strategy: Find the area of each room. Multiply each length and width 12 x 10 = 120 square feet 16 x 15 = 240 square feet 10 x 9 = 90 square feet

Example 1 Jake is laying carpet in three rooms of his house. The dimensions of the room are 12 feet by 10 feet, 16 feet by 15 feet and 10 feet by 9 feet. How many square feet of carpet will be needed? Strategy: Find the area of each room. Multiply each length and width 12 x 10 = 120 square feet 16 x 15 = 240 square feet 10 x 9 = 90 square feet Add the area of each room to get the total area = 450 square feet Solution: Jake will need 450 square feet of carpet

Solving Word Problems Sometimes drawing a sketch or table is helpful.

Example 2 East Tower is 25 feet taller than Middle Manor, which is 40 feet taller than Base Building. Base Building is 60 feet tall. How tall is East Tower?

Example 2 East Tower is 25 feet taller than Middle Manor, which is 40 feet taller than Base Building. Base Building is 60 feet tall. How tall is East Tower? 25 ft 40 ft 60 ft ET MM BB

Example 2 East Tower is 25 feet taller than Middle Manor, which is 40 feet taller than Base Building. Base Building is 60 feet tall. How tall is East Tower? 25 ft 40 ft 60 ft ET MM BB Add each additional height. 60 feet = 125 feet East Tower is 125 feet tall

Example 3 The soccer team bought 600 candy bars for $0.50 each. If the team sells the bars for $2.00 each, what will be the total profit?

Example 3 The soccer team bought 600 candy bars for $0.50 each. If the team sells the bars for $2.00 each, what will be the total profit? 1 method is to take the cost of the candy bars away from the revenue. 600 x $2 = $ x $0.50 = 300 Profit = $1200 – $300 = $900

Example 3 The soccer team bought 600 candy bars for $0.50 each. If the team sells the bars for $2.00 each, what will be the total profit? A second method is to find the profit of each candy bar and multiply that times the number of bars sold. $2 - $0.50 = $ x $1.50 = $900 Profit = $900

Example 4

= 270 total in expenses 270/4 people = $67.50 each

Example 5

I see this as a square that she walks along, with 2 extra 1 mile lines. This makes a total of 10 miles for the course. She jogs this course 3 times each week so 3 x 10 = 30 miles

Example 6

Distance = rate x time 600miles = 50miles per hour x time 600miles/50miles per hour = 12 hours

Example 7

187 x 3.75 = x 5.25 = = $

Example 8

6 x 1.25 = = – = $11.20

Example 9

.40 profit on each pen 400 x.40 = 160

Example 10

2 x 1.59 = x 2.79 = = 11.55

Example 11

ST ESB 200 feet SN 645 feet 1450 – 200 – 645 = 605 feet

Estimating Estimation can make the calculations easier to do. Round your values to estimate an answer. Round your values to see if an answer makes sense.

Example 1

Example 2

Example 3 A family went out to dinner. Their bill, including tax was $ They left a 15% tip. What was the approximate cost of the dinner, including tip?

Example 3 A family went out to dinner. Their bill, including tax was $ They left a 15% tip. What was the approximate cost of the dinner, including tip? Round $67.13 to the nearest $10 70 x.15 = = The total cost was approximately $80.50