Multiples of Nine

By:Krista Smith

Bell was in a 4th grade class.She loved her teacher very much.

They learned all sorts of interesting thingsabout the weather, and history and such.

Welcome to 4th Grade!

Teacher

She enjoyed almost every subjectincluding writing, science and Texas history.

But when it came to math,well… that was a different story.

Bell was great at additionand even pretty good at subtraction.

But there was one thing that she struggled withand that was multiplication.

12 + 8 = 20

45 - 26 = 19

32 - 15 = 17

14 + 19 = 33

Twos, fives and tens were easy.She was even pretty good at fours and threes.

But when Bell had to multiply by nines,she felt like she had a disease.

5 X 6 = 30 10 X 7 =

70

9 X 6 = ?

2 X 4 = 8

She would begin to feel quite dizzyand her tummy began to feel sick.

Even though she had practiced her facts,the information just wouldn’t stick!

One day the class was doing mad minutes.It was so hard Bell just hung her head.

Sam noticed her looking sad.“What’s wrong?” he said.

“Well then I have a trick to teach you,” said Sam.“You’re going to be just fine.”

“Multiplication is just so hard,” Bell explained.“Especially multiples of nine.”

“Decide which number you want to multiply by nineand then hold out your hands.

Count to that number using your fingersbut wait, there’s something else you must understand.”

“You have to count from left to rightor the trick wont go as planned.

Then fold the finger you counted to downand the answer will be on your hand.”

R I G H T

L E F T

“I’ll prove it to you,” said Sam.

“Let’s solve 9 X 2!”

“That can’t possibly work,” said Bell.“It’s just too easy to be true.”

Sam held out his handsAnd counted to his second finger.

“Now when I fold this finger down,there the answer will linger.”

“The number of fingers to the leftIs the number you’ll put in the tens place.”

1

9 X 2 = 1

“And the number of fingers to the rightrepresents the ones space.”

1 2

3 4

5 67

8

9 X 2 = 1 8

“Oh my goodness!” Bell said,“I can see it now so clear!

Never again will I struggle with this.I can multiply by nine without fear!”

9 X 2 = 18

“Okay,” said Sam, “What do you want to do?”

Bell suggested 9 X 4!”

“Let’s do another example,” said Bell“I can’t wait to learn some more!”

.

“Count 4 over and fold that finger down” said Sam.“Now which answer will you pick?”

“Well there’s 3 to the left and 6 to the rightSo that means the answer is 36!”

1

23

1 2

3 45

6

9 X 4 = 3 6

“Alright,” said Sam. “Do you want me to help?”

Bell just said, “no, not this time.”

“Let’s do it again!” Bell exclaimed with glee.“This time let’s find 8 X 9!”

She counted 8 fingers over and then folded it downThen she glanced from left to right.“The answer is 72!” Bell screamed.

Sam just smiled and said, “you’re bright!”

1

23 4

5 6

7 12

9 X 8 = 7 2

,

Ever since that memorable dayBell has done great in math!All because she found a trickTo multiply by nine in a flash!

9 X 2 = 189 X 3 = 279 X 4 = 369 X 5 = 459 X 6 = 549X 7 = 639X 8 = 729 X 9 = 81

TEKS

• 111.16 Mathematics, Grade 4 (b) Knowledge & Skills, (4.4) Number, operation, and quantitative reasoning. The student multiples and divides to solve meaningful problems involving whole numbers. The student is expected to: (D) Use multiplication to solve problems (no more than two digits times two digits without technology).

• 111.16 Mathematics, Grade 4 (b) Knowledge & Skills, (4.6) Number, operation, and quantitative reasoning. The student uses patterns in multiplication and division. The student is expected to: (A) Use patterns and relationship to develop strategies to remember basic multiplication and division facts (such as patterns in related multiplication and division number sentences (fact families) such as 9X9=81 and 81/9=9)