## Friday, May 13, 2011

### Math problems of the week: 6th grade Everyday Math vs. Singapore Math

I. The "Percent Problems" set in the 6th grade Everyday Math Student Math Journal Volume 1, p. 157:

Math Message

A CD that regularly costs \$15 is on sale for 20% off.
a. What is the discount in dollars?       ___________
b. What is the sale price?                  ___________

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Do not use a calculator to solve problems 3-5.

3. A boom box that costs \$120 is on sale for 25% off.
a. What is the discount in dollars?       ___________
b. What is the sale price?                  ___________

4. A bank gives interest of 5% a year.
a. What is the interest on \$100.00?
b. What is the interest in \$500.00?
c. What is the interest on \$1,000.00?

5. The \$2.50 price of a hot dog at a major league baseball park is shared as follows:
20% pays for the hot dog, bun, and fixings
20% pays for the concession stand workers
10% is the profit for the concession stand owner
10% pays for cleaning and other costs
40% goes to the team and stadium owners

a. How much do the hot dog, bun, and fixings cost?  ___________
b. How much do the team and stadium owners get?  ___________
c. How much does the concession stand owner get?  ___________

Source: Zillions Magazine

You may use a calculator to solve the rest of the problems.

6. A CD that regularly costs \$14.95 is on sale for 20% off.
a. What is the discount in dollars?                    ___________
b. What is the sale price?                               ___________

II. The first percent word problems in the 6th grade Singapore Math Primary Mathematics 6A, pp. 48-53:

Exercise 17

1. There are 25 girls, 18 boys and 7 adults on a bus. What percentage of the people on the bus are adults?

2. Ben, Mingli and Samy shared \$120. Ben received \$45, Mingli received \$63 and Samy received the rest. What percentage of the money did Samy receive?

3. Duncan spent \$480 on a television set and had \$320 left. What percentage of his money did he spend on the television set?

4. 400 students were asked to choose their favorite games. 26% of them chose baseball, 12% basketball, 10% volleyball and the rest chose soccer. How many students chose soccer as their favorite game?

Exercise 18

1. Aminah had \$120. She spent 20% of the money on food and 25% of the remaining on clothes.

a. What percentage of the money did she have left?

b. How much money did she have left?

2. There were 1500 people at a concert. 55% of them were men, 20% of the remainder were women and the rest were children. How many children were there?

Exercise 19

1. 5000 people visited  a book fair in the first week. The number of visitors was increased by 10% in the second week. How many people visited the book fair in the second week?

2. The usual price of a washing machine was \$400. As a sale, the price was reduced by 25%. What was the price of the washing machine at the sale?

3. Kendall bought a vase that cost \$450. In addition, she had to pay a 3% sales tax. How much did she pay for the vase?

4. There were 24 boys and 20 girls in a chess club last year. This year the number of boys in the club was increased by 25% but the number of girls was decreased by 10%. Find the overall increase or decrease in the membership of the club.

III. Extra Credit

What percentage of Everyday Math students will opt to use a calculator for problem 6 in the Everyday Math problem set?

What percentage of Everyday Math students are capable of solving the Singapore Math problems if they're allowed to use a calculator?