Ann Whitehead Nagda - Cheetah Math. Learning About Division from Baby Cheetahs

O H, BOY ! C AN I CHASE THE KITTY ?

W ANT TO SEE MY CLAWS ?

M AJANI JUMPS ON HIS SISTER .

N OW WHAT ?

CHEETAH MATH

L EARNING ABOUT D IVISION FROM B ABY C HEETAHS

BY A NN W HITEHEAD N AGDA

IN COLLABORATION WITH THE S AN D IEGO Z OO

Henry Holt and Company

New York

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T HE CHEETAHS WATCH A DOG THROUGH THE SCREEN WHILE TRAINER S USIE E KARD REASSURES THEM .

Since 1981, more than 130 cheetahs have been born at the San Diego Zoos Wild Animal Park. Recently, two of its cheetah cubs had to be hand-raised at its sister facility, the San Diego Zoo. Each cub was paired with a dog, so they could be trained as animal ambassadors who meet the Zoo and Park visitors and help to educate them about the plight of wild cheetahs. The dog buddies helped the cheetahs stay calm around strangers. This book uses division to tell the story of the cubs and their dogs.

T IME FOR A BOTTLE .

9 OUNCES OF MILK FOR K UBALI

9 OUNCES OF MILK FOR M AJANI

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.

S ENIOR NURSERY KEEPER J ANET H AWES TAKES CARE OF THE CHEETAH CUBS .

Late in November 2001, two baby cheetahs were born at the San Diego Zoos 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 wasnt 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.

J ANET H AWES FEEDS ONE OF THE 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:

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.

15 OUNCES = 5 EQUAL GROUPS OF 3 OUNCES EACH

A cub got 3 ounces of milk at each feeding.

O NE CHEETAH CUB PLANS A SURPRISE ATTACK .

Soon the cubs began to swat at and wrestle with each other. Majani liked to play rough. His tail would shake like a rattlesnakes when he thought about pouncing on his sister. If Kubali was busy grooming herself, she wouldnt realize that her brother was sneaking up behind her. Hed also hide behind a corner and pounce when she walked by. Kubali was calmer than her brother and liked to sit on a keepers lap. She purred loudly while the keeper stroked her fur.

Y UCK ! M EAT !

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 Kubalis meat, so she wouldnt 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.