Susan Conover BRAIN TEASERS MATH BRAIN TEASERS · PDF fileDaily Warm-Ups: Math Brain Teasers ... Leon has done the first three views. Can you combine them to do the fourth view, showing

MATH BRAIN TEASERS

Susan Conover

MATH BRAIN TEASERS

Susan Conover

ii ii iiTable of Contents

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Numbers, Numeration, Operations, and Patterns . . . . . . 1

Geometry and the Coordinate Plane . . . . . . . . . . . . . . . 36

Money . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Data Analysis, Statistics, Combinations, and Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Fractions, Ratios, Decimals, and Percents . . . . . . . . . . 156

ii ii iiTable of Contents

DDaaii llyy WWaarrmm--UUppss:: MMaatthh BBrraaiinn TTeeaasseerrss

Numbers, Numeration, Operations, and Patterns . . . . . . 1

Geometry and the Coordinate Plane . . . . . . . . . . . . . . . 36

Money . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

Data Analysis, Statistics, Combinations, and Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Fractions, Ratios, Decimals, and Percents . . . . . . . . . . 156

If today is April 23, 2006, write the exact age of a personborn on March 9, 2001, using the Mayan method of calendartime. (Assume there are no leap years.)

The Mayans of Mexico used a method of dots and lines to show aperiod of time. Each dot represents a unit, and each bar represents5 units. From the bottom position to the top position, the symbolsrefer to the number of days, months, and years, respectively. Theexample below shows 15 years, 11 months, and 8 days.

© 2005 Walch Publishing

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(15 years)

(2 � 5 + 1 = 11 months)

(3 + 5 = 8 days)

If today is April 23, 2006, write the exact age of a personborn on March 9, 2001, using the Mayan method of calendartime. (Assume there are no leap years.)

The Mayans of Mexico used a method of dots and lines to show aperiod of time. Each dot represents a unit, and each bar represents5 units. From the bottom position to the top position, the symbolsrefer to the number of days, months, and years, respectively. Theexample below shows 15 years, 11 months, and 8 days.


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(15 years)

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Prime factorization is finding the factors of a number that are allprime numbers.

To find the prime factors of a number, you start by finding twofactors. If either factor is not a prime number, find factors for thatfactor. Continue the process until all your factors are prime.

Find factors and multiples that will correctly complete the primefactorization diamond below. Hint: The same number appears inthe boxes at both ends.

©2005 Walch Publishing

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Prime factorization is finding the factors of a number that are allprime numbers.

To find the prime factors of a number, you start by finding twofactors. If either factor is not a prime number, find factors for thatfactor. Continue the process until all your factors are prime.

Find factors and multiples that will correctly complete the primefactorization diamond below. Hint: The same number appears inthe boxes at both ends.


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It is said that a picture is worth a thousand words. Sometimes, youcan make words act like pictures. This shows their meaningsvisually. For example, perpendicular lines are lines at right anglesto each other. So you might write the term like this:

Try your hand at being clever. Think of a fun way to write thefollowing words.

obtuse perimeter

acute volume

equilateral triangle


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It is said that a picture is worth a thousand words. Sometimes, youcan make words act like pictures. This shows their meaningsvisually. For example, perpendicular lines are lines at right anglesto each other. So you might write the term like this:

Try your hand at being clever. Think of a fun way to write thefollowing words.

obtuse perimeter

acute volume

equilateral triangle



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Leon was preparing drawings for a new building. He had to drawfour separate views: one from directly in front; one from directlyabove; one directly from the side; and one at an angle, showingthe building in perspective.

Leon has done the first three views. Can you combine them to dothe fourth view, showing the completed building?



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Front Top Side

Leon was preparing drawings for a new building. He had to drawfour separate views: one from directly in front; one from directlyabove; one directly from the side; and one at an angle, showingthe building in perspective.

Leon has done the first three views. Can you combine them to dothe fourth view, showing the completed building?



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Front Top Side

What is the measure of the exterior angle of the isosceles-shapedtepee?



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What is the measure of the exterior angle of the isosceles-shapedtepee?



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If the crank is turned clockwise, which way should the hamster run?



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If the crank is turned clockwise, which way should the hamster run?



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The rules of a coin game state that a move is a jump over one ortwo coins at a time. What is the smallest number of moves itwould take to get the following coins in the order P–P–P–N–N–N,with no gaps between coins?


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The rules of a coin game state that a move is a jump over one ortwo coins at a time. What is the smallest number of moves itwould take to get the following coins in the order P–P–P–N–N–N,with no gaps between coins?


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A counterfeiter was trying to print his own money, and he cameup with this version of a dollar bill. However, he has made a fewmistakes. Can you find four errors on this fake bill?


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A counterfeiter was trying to print his own money, and he cameup with this version of a dollar bill. However, he has made a fewmistakes. Can you find four errors on this fake bill?


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Little Red Riding Hood’s grandmother has given her a big jar that

she has been using to collect coins. Among the coins are 18

quarters. Her grandmother says that she can have all the coins if

of the quarters go into her college savings account, of

them go toward a new CD player, and go toward something

fun. After happily agreeing to this, Little Red digs through the

quarters and finds that one quarter is actually a subway token.

How many quarters should go in each category?


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Little Red Riding Hood’s grandmother has given her a big jar that

she has been using to collect coins. Among the coins are 18

quarters. Her grandmother says that she can have all the coins if

of the quarters go into her college savings account, of

them go toward a new CD player, and go toward something

fun. After happily agreeing to this, Little Red digs through the

quarters and finds that one quarter is actually a subway token.

How many quarters should go in each category?


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You may have heard the story of how Hannibal crossed the Alpswith an army and a number of elephants. To move all his supplies,he must have used carts as well as elephants.

Imagine that some of Hannibal’s carts had three wheels, one in thefront and two in the back. For safety, each had a spare wheel, andthe wheels were rotated so that all four wheels got the sameamount of wear.

If Hannibal’s entire route was 1,000 miles long, how many miles ofwear were put on each wheel?


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You may have heard the story of how Hannibal crossed the Alpswith an army and a number of elephants. To move all his supplies,he must have used carts as well as elephants.

Imagine that some of Hannibal’s carts had three wheels, one in thefront and two in the back. For safety, each had a spare wheel, andthe wheels were rotated so that all four wheels got the sameamount of wear.

If Hannibal’s entire route was 1,000 miles long, how many miles ofwear were put on each wheel?



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What is the area of the shaded portion of the circle?



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7 in.

What is the area of the shaded portion of the circle?



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Berto’s Buckets manufactures buckets in many different sizes. Berto is trying to describe all the sizes in a certain product line to a customer, but he has forgotten a few. The sizes increase accordingto a regular pattern.

Help Berto find the sizes of the missing buckets.

Size 1 Size 2 Size 3

1 quart 1 gallon ________________


4 gallons ________________ 9 gallons



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Berto’s Buckets manufactures buckets in many different sizes. Berto is trying to describe all the sizes in a certain product line to a customer, but he has forgotten a few. The sizes increase accordingto a regular pattern.

Help Berto find the sizes of the missing buckets.


1 quart 1 gallon ________________


4 gallons ________________ 9 gallons



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Complete the proverb by first unscrambling the letters to makewords. Then use the letters in the circles to form another newword. This word completes the proverb.

“___ ___ ___ ___ waits for no man.”

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Complete the proverb by first unscrambling the letters to makewords. Then use the letters in the circles to form another newword. This word completes the proverb.

“___ ___ ___ ___ waits for no man.”

RAYE

HNMTO

TYECNUR

ILNINMELUM



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What is the perimeter of the net that could be folded to form this box?



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4 meters

5 meters

6 meters

What is the perimeter of the net that could be folded to form this box?



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4 meters

5 meters

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Find the decimal word parts hidden in the puzzle below.

Meaning Word Part Meaning Word Part

kilo- 1,000 deci-

hecto- 100 centi-

deka- 10 milli-



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Find the decimal word parts hidden in the puzzle below.

Meaning Word Part Meaning Word Part

kilo- 1,000 deci-

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All the students in a science class also take a math class. Half ofthe students who play baseball also take a math class. One-quarterof the students in the math class also take a science class. Sixtystudents play baseball. Forty students take a science class. Nobodywho plays baseball takes a science class.

How many students who take a math class neither take a scienceclass nor play baseball?


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All the students in a science class also take a math class. Half ofthe students who play baseball also take a math class. One-quarterof the students in the math class also take a science class. Sixtystudents play baseball. Forty students take a science class. Nobodywho plays baseball takes a science class.

How many students who take a math class neither take a scienceclass nor play baseball?




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In a first-grade class, a teacher places the following cards on atable.

He then flips the cards over and mixes them up. He asks astudent to pick up cards randomly and turn them over until shecan make the word CAT.

What is the probability of the student making the wordCAT on her first try without replacing any cards?




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A A A A C C T T T

In a first-grade class, a teacher places the following cards on atable.

He then flips the cards over and mixes them up. He asks astudent to pick up cards randomly and turn them over until shecan make the word CAT.

What is the probability of the student making the wordCAT on her first try without replacing any cards?




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A A A A C C T T T

In genetics, some traits are dominant, and some are recessive. Adominant gene is shown with a capital letter. A recessive gene is

shown with a small letter. If someone inherits both a dominantgene and a recessive gene for the same trait, the dominant gene will

appear. The recessive gene only appears if the person inherits tworecessive genes for the trait.

A woman with brown eyes (Bb) marries a man with blue eyes (bb). Theydecide to have children. The square shows the possible combinations of genesfor eye color their children could receive.

If the woman and her husband have 3 children, what are the chances thatall 3 children will have blue eyes?




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In genetics, some traits are dominant, and some are recessive. Adominant gene is shown with a capital letter. A recessive gene is

shown with a small letter. If someone inherits both a dominantgene and a recessive gene for the same trait, the dominant gene will

appear. The recessive gene only appears if the person inherits tworecessive genes for the trait.

A woman with brown eyes (Bb) marries a man with blue eyes (bb). Theydecide to have children. The square shows the possible combinations of genesfor eye color their children could receive.

If the woman and her husband have 3 children, what are the chances thatall 3 children will have blue eyes?




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Documents

Susan Conover BRAIN TEASERS MATH BRAIN TEASERS · PDF fileDaily Warm-Ups: Math Brain Teasers ... Leon has done the first three views. Can you combine them to do the fourth view, showing