Cheetah Math: Learning About Division from Baby Cheetahs

by Ann Whitehead Nagda

Overview

Cheetahs are very fast—and very shy. When two young cubs come to the nursery at the San Diego Zoo, the staff hopes they will help visitors learn more about the plight of cheetahs in the wild. Majani and Kubali are shy, but with the help of their dog buddies they become perfect animal ambassadors.

In Cheetah Math, kids can learn all about division from these baby cheetahs and their canine friends.

A Junior Library Guild Selection

Product Details

ISBN-13:	9781466867253
Publisher:	Henry Holt and Co. (BYR)
Publication date:	04/01/2014
Series:	Animal Math Series
Sold by:	Macmillan
Format:	eBook
Pages:	32
File size:	7 MB
Age Range:	7 - 10 Years

About the Author

Ann Whitehead Nagda is the author of math picture books about baby zoo animals, including Polar Bear Math and Panda Math, as well as several other books about wildlife. She lives in Boulder, Colorado.

The San Diego Zoo is recognized as one of the world's premier animal parks. The zoo's efforts help protect the survival of animals in captivity and those in the wild through research and education.

Ann Whitehead Nagda is the author of math picture books about baby zoo animals, including Panda Math and Cheetah Math, as well as several other books about wildlife. She lives in Boulder, Colorado.

Read an Excerpt

Cheetah Math

Learning About Division From Baby Cheetahs

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By Ann Whitehead Nagda

Henry Holt and Company

Copyright © 2007 Ann Whitehead Nagda
All rights reserved.
ISBN: 978-1-4668-6725-3

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CHAPTER 1

SHARING THE MILK

TIME FOR A BOTTLE.

9 OUNCES OF MILK FOR KUBALI

9 OUNCES OF MILK FOR MAJANI

18 OUNCES = 2 EQUAL SHARES OF 9 OUNCES EACH

Division means splitting something into a number of equal parts. The nursery keeper mixed powdered kitten formula with water, making 18 ounces of milk to feed the two cheetah cubs on their first day in the nursery. The milk was divided into 2 equal parts, or shares. The figure above shows that 18 ounces can be divided into 2 equal shares of 9 ounces each. Each cub was offered 9 ounces of milk.

The dividend is the number being divided into equal parts. The divisor is the number of parts you want to split the dividend into. The result of the division is called the quotient. In this equation, the dividend is 18, the divisor is 2, and the quotient is 9.

Late in November 2001, two baby cheetahs were born at the San Diego Zoo's Wild Animal Park. When the cubs were ten days old, their mother became too ill to care for them, so they were taken to the San Diego Zoo nursery to be hand-raised. The male cheetah was named Majani, which means "grasslands" in Swahili, and his sister was named Kubali, which means "accepting."

At first the cheetahs hissed at everyone in the nursery because they were scared. But it wasn't long before they felt comfortable. After feeding each cub a bottle, nursery keeper Janet Hawes snuggled with them while they purred and licked her fingers. With their bellies full of warm milk, the cubs soon fell asleep.

CHAPTER 2

HUNGRY CUBS

When the cheetah cubs were six weeks old, they drank more milk and could go longer between feedings. Each cub drank 15 ounces of milk a day, divided into 5 feedings.

How much milk did a cub get at each feeding? Because there are 5 feedings, you need to divide 15 ounces by 5. The problem could be written like this:

15/5 = DIVIDEND/DIVISOR

One way to solve this problem is to dole out the ounces of milk into 5 equal groups. Each group contains the milk for one feeding. In the chart below, you can see that 15 ounces can be divided into 5 feedings of 3 ounces each.

3 OUNCES FOR THE 1ST FEEDING

3 OUNCES FOR THE 2ND FEEDING

3 OUNCES FOR THE 3RD FEEDING

3 OUNCES FOR THE 4TH FEEDING

3 OUNCES FOR THE 5TH FEEDING

15 OUNCES = 5 EQUAL GROUPS OF 3 OUNCES EACH

A cub got 3 ounces of milk at each feeding.

Soon the cubs began to swat at and wrestle with each other. Majani liked to play rough. His tail would shake like a rattlesnake's when he thought about pouncing on his sister. If Kubali was busy grooming herself, she wouldn't realize that her brother was sneaking up behind her. He'd also hide behind a corner and pounce when she walked by. Kubali was calmer than her brother and liked to sit on a keeper's lap. She purred loudly while the keeper stroked her fur.

CHAPTER 3

DAYS INTO WEEKS

The cubs started eating some meat when they were 49 days old. At first, Janet Hawes gave them fine threads of meat or tiny meatballs. Neither cub liked the food, but Majani ate more than Kubali. Janet had to mix a little milk with Kubali's meat, so she wouldn't spit it out.

How many weeks old were the cubs at 49 days? Because there are 7 days in a week, you need to divide 49 days by 7 to figure out the number of weeks. Here the divisor, or 7, is the number of days in a week, and the quotient, or answer, will give you the number of weeks.

49 ÷ 7 = ?

From the chart below, you can see that 49 can be divided into 7 equal groups of 7 days each. The cubs were 7 weeks old when they began to eat meat.

7 X 1 = 7
7 X 2 = 14
7 X 3 = 21
7 X 4 = 28
7 X 5 = 35
7 X 6 = 42
7 X 7 = 49

49 DAYS = 7 EQUAL GROUPS OF 7 DAYS EACH

Cheetahs are very sensitive animals. When someone new came into the nursery, the cubs would hide behind the keeper and peer around her legs at the stranger. In order for the shy cubs to cope with new places and people as animal ambassadors, they each needed a "big brother" to keep them calm. And the perfect "big brother" was an easygoing, smart, and people-friendly dog. The Zoo had successfully paired cheetahs and dogs several times before. By watching the dog's body language — its wagging tail and perked-up ears — a cheetah can tell immediately that a new situation is okay.

CHAPTER 4

HOW BIG AM I?

You can use division to compare things. A cheetah named Arusha weighed 11 pounds when he was introduced to his dog. Anna, the dog, weighed about 44 pounds. For a cheetah to accept the dog as the alpha, or leader, the dog has to be bigger.

How many times bigger was the dog than the cheetah? You will need to divide 44 pounds by 11 pounds to find the answer. One way to do this is to use repeated subtraction. Take 44 and keep subtracting 11 until you can't subtract it anymore. Then count how many times you subtracted 11.

You can subtract 11 pounds from 44 pounds 4 times, so you know that Anna is 4 times bigger than Arusha.

44 LBS. = 11 LBS. + 11 LBS. + 11 LBS. + 11 LBS.

44 POUNDS = 4 EQUAL GROUPS OF 11 POUNDS EACH

Anna and Arusha were the first dog and cheetah paired together at the San Diego Zoo. Arusha, a male cheetah, had been hand-raised in Oregon and was brought to San Diego in 1981, when he was three months old. He was used to being around humans and "chirped" in distress whenever he was alone. The cheetah cub was paired with Anna, a golden retriever, who had been donated to the Zoo after failing obedience training. Within a few months, Anna and Arusha became inseparable. During the thirteen years that they lived together, they met movie stars, kings and queens, and millions of Zoo visitors. Anna kept her cheetah pal calm and contented no matter what the occasion.

CHAPTER 5

ARE WE BIG ENOUGH?

Majani and Kubali weighed about 16 pounds each when they met their dogs, Bear and Clifford. The dogs were a few months older and weighed about 49 pounds each. How many times bigger were the dogs than the cheetahs? In other words, how much is 49 pounds divided by 16 pounds?

49 ÷ 16 = ?

You can use repeated subtraction to solve this problem. Start by subtracting 16 from 49. Keep subtracting 16 until you can't do it anymore.

You can subtract 16 pounds from 49 pounds 3 times — but there is 1 pound extra. Many numbers are not evenly divisible by other numbers, so there is something left over. This is called the remainder. Since you were able to subtract the cheetah's weight 3 times, with only a small remainder, then you know that the dogs are about 3 times bigger than the cheetahs.

49 LBS. = 16 LBS. + 16 LBS. + 16 LBS. + 1 LB.

49 POUNDS = 3 EQUAL GROUPS OF 16 POUNDS EACH WITH

A REMAINDER OF 1 POUND

The trainers chose two puppies from the San Diego Humane Society to be companions for Majani and Kubali. Since each dog had to be considered the alpha, or leader, of the cheetah-dog pair, the dogs had to be several months older than the cheetahs and larger as well. Clifford, who was part Labrador, had been returned after an adoption that didn't work out. He was a very energetic dog and could play all day long. Majani was more outgoing and playful than his sister and he seemed to prefer Clifford.

CHAPTER 6

YUMMY MEAT

When the cubs were older, they stopped drinking milk and ate more meat. Together the two cheetahs ate 44 ounces of meat in a day. How many ounces did each cheetah eat? To find the answer, you need to divide 44 ounces by 2 cheetahs.

44 ÷ 2 = ?

One way to solve this problem is to divide the tens first and then the ones. There are 4 tens in 44. Take the 4 tens and divide by 2. When you divide 40 by 2, you get 20.

40 ÷ 2 = 20

Now divide the 4 ones by 2. When you divide 4 by 2, you get 2.

4 ÷ 2 = 2

Add the results together.

20 + 2 = 22

There are 2 equal shares of 22 ounces in 44 ounces. Each cheetah ate 22 ounces in one day.

44 OUNCES = 2 EQUAL SHARES OF 22 OUNCES EACH

Kubali seemed more comfortable with the second dog, a chow-retriever mix named Bear. He'd been wandering around San Diego by himself before he was taken to the humane society. At first, Kristi Dovich, one of the trainers, worried that Bear wasn't outgoing enough. He seemed mopey and depressed. She hoped that life at the Zoo would make him happier.

There was another problem, too. Majani and Kubali were already bonded to each other. The two cheetahs continued to live and play together after they met their dog companions. Would either cub ever accept a dog as a buddy?

CHAPTER 7

GROWING UP

Cheetah cubs in the wild stop drinking milk when they are around 16 weeks old. Kubali and Majani were 105 days old when they stopped drinking milk. How many weeks old were they? Because there are 7 days in a week, you need to divide 105 days by 7 to find out.

105 ÷ 7 = ?

One way to figure this out is to break apart the dividend, 105, into two numbers. First find a number that is easy for you to divide into 7 equal parts. You know that 7 multiplied by 10 is 70, so make 70 the first number. There are 10 equal groups of 7 days each in 70 days.

7 x 10 = 70

When you subtract 70 days from the total of 105 days, you are left with 35 days.

105 - 70 = 35

Now you need to find out how many groups of 7 days are in 35 days. Count up by 7's: 7, 14, 21, 28, 35.

7 x 5 = 35

So there are 5 equal groups of 7 days in 35 days. To find out the total number of weeks, you need to add the two results together.

10 WEEKS + 5 WEEKS = 15 WEEKS

Since there are 15 equal groups of 7 days each, the cheetah cubs were 15 weeks old when they stopped drinking milk.

105 DAYS = 15 EQUAL GROUPS OF 7 DAYS EACH

For a while, the training sessions were very short. The dog and cheetah would be brought together for only five or ten seconds. Sometimes the dogs would just be near their cheetah partners. As the cheetahs became more relaxed, the sessions grew longer. Kubali and Majani even began to follow their dogs. When one of the dogs would stop walking, his cheetah partner would sometimes nudge up against him to get him to play.

CHAPTER 8

FAST CAT

Cheetahs are built to run. They can run faster than any other land animal, reaching top speeds of 70 miles per hour. Kubali and Majani have been trained to chase a fake rabbit. Sometimes their dogs get to run, too. Trainers have clocked Clifford running at 31 miles per hour, but they haven't been able to measure the speeds of Majani and Kubali. The cheetahs are so fast that they get out of range before the radar gun can read their speeds. If the cheetahs run at top speed, how many times faster do they run than Clifford? The division problem looks like this:

70 ÷ 31 = ?

One way to solve this is to use repeated subtraction. Subtract 31 from 70, which is 39. Subtract 31 from 39, which is 8. You subtracted 31 two times with 8 left over. This means that 70 miles per hour can be divided into 2 equal groups of 31 with a remainder of 8.

The cheetahs can run slightly more than two times as fast as the dog.

Little by little, the dogs and cheetahs learned to get along. Majani learned not to swat or pounce on Clifford's tail. And Clifford learned not to tackle or bark at Majani. But they still needed reminders about playing nicely together. Trainer Kristi Dovich said "uh uh uh" so often while training Majani and Clifford that Chico, a scarlet macaw who lived nearby, started saying "uh uh uh," too. Finally, after three months, each dog was ready to spend the entire day with his cheetah.

CHAPTER 9

BIG, BULGING TUMMIES

Cheetahs in a zoo get fed every day. In the wild, they might make a kill only every few days and then they have to eat fast before lions or hyenas steal their meal. An adult cheetah in the wild can eat 30 pounds in one sitting — and looks like it's swallowed a basketball. An adult tiger can eat as much as 90 pounds of meat at a time. How many times more meat can a tiger eat than a cheetah? To figure this out, you need to divide 90 pounds by 30 pounds.

90 ÷ 30 = ?

You can show the total weight of 90 pounds as 9 tens. Dole out the tens into groups of 30 pounds each, so that each group has 3 tens in it.

3 TENS 3 TENS 3 TENS

You can see that there are 3 groups of 3 tens each, so you know that 90 divided by 30 is 3. An adult tiger can eat 3 times as much meat as a cheetah.

90 LBS. MEAT = 30 LBS. MEAT + 30 LBS. MEAT + 30 LBS. MEAT

90 POUNDS = 3 EQUAL GROUPS OF 30 POUNDS EACH

The real bonding did not occur until the cheetahs began to live full-time with their dogs. Majani and Clifford, who now live at the San Diego Zoo's Wild Animal Park, get along well in a brotherly way, but Kubali and Bear are more affectionate. Kubali sucks on Bear's head, licking him up one side and down the other. After she's finished grooming him, Bear's ears are soaking wet. Kubali tolerates Bear's leaping and tackling, but when she's had enough, she smacks him on the nose or just lies still. She does like to play, though. Sometimes she'll drop a toy in front of him just so she can steal it back.

CHAPTER 10

GROWN-UP CHEETAHS

Kubali and Majani are now full-grown adults. Majani is a very large cheetah, weighing in at 144 pounds. His sister weighs a dainty 122 pounds. What is the average of their two weights?

An average, or arithmetic mean, gives you one central value that represents several numbers. You find an average by adding up the group of numbers and then dividing that sum (or total) by the number of items in the group.

To find the average weight of the two cheetahs, add 122 pounds and 144 pounds. The sum of their weights is 266 pounds. Since there are two cheetahs, divide 266 pounds by 2.

266 ÷ 2 = ?

One way to solve this division problem is to show the combined weight of 266 pounds as 2 hundreds, 6 tens, and 6 ones. Take the hundreds first and divide them into two equal groups of 1 hundred each. Next take the 6 tens and divide them into two groups of 3 tens each. Finally take the 6 ones and divide them into two groups of 3 ones each.

So each group looks like this:

100 + 30 + 3 = 133

You can see that in each group, you have 1 hundred, 3 tens, and 3 ones. When you add the hundred, tens, and ones together, you find that each group contains 133 pounds.

So the average weight of the two cheetahs is 133 pounds.

Because dogs are more active than cats, Bear and Clifford spend time away from their cheetahs, playing with people or other Zoo dogs. While her dog is away, Kubali is given something to keep her busy, like a yummy bloodsicle, made by freezing blood and water together. But if Bear is gone too long, Kubali gets lonely and will chirp for him.

Bear turned out to be the perfect buddy for Kubali. Even though Kubali is now forty pounds heavier than Bear and could easily make a meal out of him, she would never do that. Kubali and her dog buddy are the best of friends. And so are Majani and Clifford.

CHAPTER 11

CHEETAHS IN TROUBLE

During the twentieth century, the cheetah population fell by an average of 800 cheetahs per year. If the cheetah population continues to fall at about the same rate, how long will it take for cheetahs to disappear completely from the wild? Take the total number of cheetahs left in 2000, which was estimated at 16,000, and divide that by 800, the number of cheetahs lost in one year.

16,000 ÷ 800 = ?

One way to solve this problem is to break apart the dividend, 16,000, into two numbers. You know that 800 multiplied by 10 is 8,000, so 8,000 cheetahs would be lost in 10 years.

800 x 10 = 8,000

When you subtract 8,000 from the total of 16,000 cheetahs, you are left with 8,000. It would take another 10 years for the remaining 8,000 cheetahs to disappear.

16,000 – 8,000 = 8,000

To find the total number of years, add 10 and 10 together.

10 + 10 = 20 YEARS

So it could take 20 years for cheetahs to disappear completely from the wild.

The line graph above shows what the cheetah population could be every 5 years, from 2000 to 2020. You can see that the cheetah population would be 16,000 in 2000, then 12,000 in 2005, 8,000 in 2010, and only 4,000 in 2015. By 2020 there could be no cheetahs left.

CLIFFORD, WHO IS WAITING NEARBY.

The cheetahs and their dogs walk around the Zoo or the Wild Animal Park several times a day with their trainers, meeting and greeting people. They also do night events and television programs and run regularly during the summer. The cheetahs aren't frightened, because their dog buddies are comfortable with new people and situations.

But this sleek cat is racing toward extinction. Most of the world's cheetahs live in Africa, where the human population has increased dramatically. Farmers destroy cheetah habitat, hunt the same animals that cheetahs do, and shoot them for killing livestock. It's possible that cheetahs could disappear from the wild in the next ten to twenty years. Let us hope that once people meet a cheetah like Kubali or Majani, they will begin to care about cheetahs and do more to keep them from disappearing in the wild.

(Continues...)

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Excerpted from Cheetah Math by Ann Whitehead Nagda. Copyright © 2007 Ann Whitehead Nagda. Excerpted by permission of Henry Holt and Company.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.

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Table of Contents

Contents

Title Page,
Copyright Notice,
INTRODUCTION,
SHARING THE MILK,
HUNGRY CUBS,
DAYS INTO WEEKS,
HOW BIG AM I?,
ARE WE BIG ENOUGH?,
YUMMY MEAT,
GROWING UP,
FAST CAT,
BIG, BULGING TUMMIES,
GROWN-UP CHEETAHS,
CHEETAHS IN TROUBLE,
About the Author,
Copyright,