Math Mysteries 22

1 point each

1. What is the remainder when 3,462 is divided by 7?

2. The area of a rectangle is 40 square centimeters. If the length of the rectangle is 8 cm, find its perimeter.

3. A rug is 10 meters long and 8 meters wide. The rug is placed into a square room of side 12 meters. What is the area of the room that is uncovered?

4. Daniel worked 6 days a week for 3 weeks. He was paid $25 a day on weekdays and twice as much on weekends. What was his total pay?

5. In a chess tournament, each competitor is to play with every other competitor once only. If there are 10 players, how many games are played. Hint: Think about the handshake problem or google it.

6. A certain number was doubled and the result was then multiplied by 3. If the product was 138, find the number. Hint: Think about flowcharts.

Math Mysteries 21

Name the integer. 1 point each

1. I am greater than -2 and less than 6, and I am a multiple of 5.
2. I am 8 less than -2 and 1 greater than -11.

Complete to make each equation true. Use each number provided only once. 1 point each (Follow the order of operations)
3. (___ x ___) ÷ ___ + ___ = 10 Use 4, 6, 2, 3
4. ___ – ___ – (___ x ___) = 5 Use 5, 10, 2, 25

5. In a certain class there are twice as many boys as girls. If the total number of students in the class is 36, how many boys are there?

6. If a toy manufacturer produces 150 Curious George toys in 30 minutes, how many Curious George toys will the toy manufacturer produce in 4 hours?

Math Mysteries 20

Techknight Plays “Street” Checkers with Ncredible

by Techknight

One day after school, Techknight and his pal Ncredible decided to have a checkers match. Techknight was the best checkers player in School 180 back in his day.

“I am an unbeatable checkers player. You can’t beat me!” claimed Techknight.

Ncredible was not impressed and accepted the challenge. Techknight was not the same player that he used to be. It had been more than a decade since he played checkers competitively, however Techknight was confident that he would win. Both players sat down and started to battle in a game of checkers. This was no ordinary checker game.

“No must jump rule.” announced Ncredible. Techknight was puzzled and said,

“There’s no such thing. That will lead to a boring game where no one has to make captures and eventually the game will end in a stalemate.”

“Are we playing or not? You are wasting time”, said Ncredible.

Techknight decided not to argue and started playing the game. Techknight took an early four piece checker lead and was smothering Ncredible. This is when Ncredible started taking advantage of the “no must jump rule.” Techknight blundered several of his checker pieces and was now struggling. Techknight had to move his king to the corner of the board so he may deploy a trap. Ncredible feared entering the trap and decided to move his pieces back and forth. This is when Techknight said,

“The game is a tie, and you are moving your pieces back and forth. We can’t be here all night.” Ncredible refused to accept the draw and continued to move his pieces back and forth.

“This is silly,” Techknight thought to himself.

“This is a TIE!”, yelled Techknight.

Ncredible continued to get Techknight angry to the point where he made a fatal mistake. Ncredible made his finishing moves on Techknight and started to celebrate his victory.

“You didn’t beat me in checkers; that was some “street” checkers game. The rules were different and unfair,” said Techknight. Ncredible said “I won and we played by the same rules” and then offered his hand and said “Good game.” Techknight shook his hand but then he went to a computer to show Ncredible the real rules.

“International, English, Spanish, Italian, Russian, and so on all have a “must jump rule.” Ncredible said “Well, I play with the no jump rule.”

“Then we didn’t play an official checkers game. You have zero chance of beating me in an official rules checkers game,” said Techknight.

“I beat you, stop crying!” said Ncredible. “Do you even know how many squares are on a checker board?” said Techknight. Ncredible quickly said “64.”

Techknight yelled,”Wrong! A great checker player like me sees beyond the 64 squares. What about the 2 by 2 square arrays, 3 by 3 square arrays, 4 by 4, and so on? You only saw the individual 1 by 1 squares.” Ncredible then pondered and asked “So how many squares are there?”

Techknight answered, “Let me show the answer mathematically. There is one 8 by 8 square. There are four 7 by 7 square. There are …” “It is after-school now, NO math please” said Ncredible. “OK, well there are hundreds”, said Techknight

Math Mysteries
1. How many squares are on an 8×8 checkerboard?

1a. If you can find the correct answer, you will get 2 points.

1b. If you can explain the correct answer you will get an additional 3 points.

2. Did Ncredible beat Techknight in “checkers” or “street checkers”? See the official rules of checkers here. 1 point

3. Who would win if Techknight and Ncredible played a checkers game following official rules? 1 point

More Math Mysteries (1 point each):

4. A recipe for punch calls for 4 cups of lemonade for every 6 quarts of fruit juice. How many quarts of fruit juice should Tayler use if she already added 10 cups of lemonade? (Hint: Proportions)

5. There are 7 girls and 15 boys in Alex’s homeroom. What percent of Alex’s homeroom are boys? Round to the nearest percent.

Translate each phrase into an algebraic expression. (1 point each)

6. $15 less than twice the cost of the video game

7. four plus five times a number

Math Mysteries 19

1. Kevin’s scores on 6 math tests were 84%, 89%, 81%, 42%, 91% and 90%. Find the mean, median, mode, and range. Which measure would give him the greatest math grade?

2. Nicholas is thinking of a number. This number is a prime number that has two digits. The sum of both digits is equal to 10. What number is Nicholas thinking of?

3. 755 – (5 + 65) x 10 =

4. Z, W, X, U, V, S, T, Q, R, O, P, M, ___,___,___ What are the next three letters in this pattern ?

Math Mysteries 18

1. What is the prime factorization of 72?

2. What is the least common multiple of 9 and 12?

Selena wrote the word mathematics on a sheet of paper.

3. What fraction of the letters are vowels?

4. What percent of the letters are consonants? (Round to the nearest percent)

5. Robert scored the following on his math tests.

86, 90, 95, 84, 94, 86, 92 What is the range of his scores?

Math Mysteries 17

Simplify: 100 / 25 x (26 + 4) x 40

George asks this riddle: “When I multiply my number by itself, I get 784. What number am I thinking of?” Solve George’s riddle.

2 points: Use the digits 1, 2, 3, and as many zeros as you want to form a division problem with a quotient(answer to a division problem) of 70.

Math Mysteries 16

1. Give a decimal which is greater than 0.273 and less than 0.291

2. What is the greatest common factor of 60, 105, and 165?

3. If the number 9,899,399 is increased by 2,082 the result will be?

4. Write 0.065 as a percent.

Math Mysteries 15

1. Anna started on the 77th floor of the Chrysler Building and rode the elevator down 18 floors, up 7 floors, and down 25 floors. What floor is Anna on now?

2. What is the G. C. F. of 16, 24, and 32?

3. Come Back for More …

Math Mysteries 14

a) Which property is shown by the equation below?

Hint: Section 1.2 in handbook
(3 + 2) + 4 = 3 + (2 + 4)

b) What is 2,709,010 written in word form?

Hint: Section 1.1 in handbook

c) A baker sells cupcakes only in boxes of 8. If he starts with 175 cupcakes and fills as many boxes as he can with cupcakes, how many cupcakes will he have left over?

d) Reduce the fraction, 432/656 to lowest terms

Math Mysteries 13

a) 4 + 6(11 – 2) /3

b) A football team gained 353 yards passing on 32 completed passes. About how many yards were gained on each pass?

c) Every 9th customer wins a book, and every 14th customer wins a Music CD. Which customer will win a book and a Music CD? (Hint: LCM)

d) In the amount of time of time it takes Stewart to complete 3 laps around the track, Techknight completes 4. If Stewart completes a total of 12 laps around the track, how many laps will Techknight complete in the same amount of time?

Math Mysteries 12

Find the LCM of 18 and 24.

Find the GCF of 60 and 45.

The first prime number is 2. What is the fourteenth prime number?

Math Mysteries 11

What is Pi?

What is the length of a side of a square with a perimeter of 36?

If each digit 5 is replaced with the digit 7, by how much will 258,546 be increased?

Math Mysteries 10

Write an algebraic expression for each statement:

A teacher is x years older than his 11 year-old students

Gym class is held twice a week during y weeks of the school year except for 5 days of assemblies

Math Mysteries 9

/ symbol equals divide

1. School starts at 8:37:30 A.M. It ends at 2:57:30 P.M. How long is the school day? Give your answer in hours and minutes.

2. If x is equal to nine, y is equal to five, and z is equal to two. What is 4(x-y)/ z?

3. (15 / 3) + (4+5) =

4. If Mr. Stew took 54 shots at a basketball hoop and made 16 baskets, what is his shooting percentage?

Math Mysteries 8

1. The same letters are the same numbers.

a x a = 25

a x b = 50

b + c = 22

a=

b=

c=

a * b * c = ?

2. Each letter stands for a 1-digit number. Find a value for each letter.

+ AAA

+ BBB

+ CCC

A=

B=

C=

Math Mysteries 7

1. A parking garage charges $0.75 an hour for parking. How long can Andy park in the garage if he only has $6 for parking?

2. The school bell rings at 8:05 A.M., 8:47 A.M., 8:50 A.M., 9:32 A.M., 9:35 A.M., 10:17 A.M., 10:20 A.M., and 11:02 A.M. If the pattern continues, what are the next three times the bell will ring?

Math Mysteries 6

September 5th, 2007

1. You purchase a shirt that costs $24.95 and a pair of gloves that cost $15.50. How much change will you receive if you give the clerk five $10 bills?

2. What is the rule for the following number pattern?

1, 5, 17, 53, 161, . . .

Math Mystery 5

August 17th, 2007

1. 2121673.22 X 1.32

2. How many hours are there in 706 days?

Hint: 24 Hours = 1 Day

3. 336921 divided by 2 is equal to?

*Remember no remainder.*

Math Mystery 4

August 3rd, 2007

Solve

1. 3,636,736 X 41.1

2. If Bobby went to the store with $136.15 and bought a pair of long shorts for $22.88, a Curious George shirt for $26.24, a New York Knights Baseball cap for $15.99, a # 1 at McDonalds for $6.32 super sized along with a 20 piece chicken nuggets at $6.20; How much change would Bobby have left?

Math Mystery 3

July 24th, 2007

1. What is the length of a side of a square with a perimeter of 36?

Hints: A square has 4 equal sides. Perimeter is the sum of all the sides.

2. The area of a rectangle is 48 and its length is 8. What is the perimeter of this rectangle?

Hints: Area = Length x Width

Perimeter is the sum of all the sides.

Math Mystery 2

July 9th, 2007

Ms. Gray, Ms. Black, and Ms. Brown are friends. Ms. Gray said, “Did you know that our names describe our hair colors, yet no one’s name matches her own hair color?” “Yes,” replied the brown-haired woman. Who has which color hair?

Math Mystery 1

June 25th, 2007

Dontae was so tired, he decided to go to bed very early. He set his alarm clock for 8:05 and went to sleep. He was surprised when the alarm rang 37 minutes later. What happened?