MATHS MISCONCEpTIONS

Minus and negative

About this course

Many people believe that ‘minus’ and ‘negative’ are the same thing. This a misconception.

This misconception is probably perpetuated by the fact that we often use the words interchangeably. But, as you will see, this hasn’t always been the case - and using 'minus' and 'negative' interchangeably doesn’t usually cause a problem so people don’t realise there is a difference between them.

In this HaileyburyX Misconceptions course we will first delve through the history of minus and negative to see their differences and similarities.

Then, we'll then explain how and why operations with negative numbers work.

Finally, we'll tackle a few specific misconceptions that people often have about minus and negative.   

The history of negative numbers

Watch this video which shows a very brief history of negative numbers, how they were written and how they are written today.

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Match the people with how they wrote negative 32

Test your knowledge.

WHO WROTE

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Wouldn’t have written it as they did not consider it as a real number.

WHO WROTE

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WHO WROTE

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WHO WROTE

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WHO WROTE

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Your score is

DEFINITION OF MINUS AND NEGATIvE

Learn the definition of minus and negative and how to explain the difference. 

ADDING 'FORTUNES' and 'DEBTS'

Learn how to add positive and negative numbers and why the rules for these operations work. 

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Adding fortunes and debts

Test your knowledge.

-10+8

3+-2

-2+3

+3+-2

+8+-10

-10++8

8+-10

-2++3

Your score is

SUBTRACTING 'FORTUNES' and 'DEBTS'

Learn how to add positive and negative numbers and why the rules for these operations work. 

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Subtracting fortunes and debts

Test your knowledge.

-5 - -4

-4--5

-7-9

-7-+9

+9--7

-4 - -5

9--7

-5--4

Your score is

MULTIPLYING 'FORTUNES' and 'DEBTS'

In this sequence of videos you will learn how multiplication works with positive numbers and how these rules dictate the rule for multiplying with negative numbers.

MULTIPLYING FORTUNES AND DEBTS PART 1

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Multiplying fortunes and debts (1)

Test your knowledge.

4x(-5)

(4)(-5)

4x-5

4x-5

Your score is

MULTIPLYING FORTUNES AND DEBTS PART 2

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Multiplying fortunes and debts (2)

Test your knowledge.

(-5)(4)

-5x4

-5x4

(-5)x4

Your score is

MULTIPLYING FORTUNES AND DEBTS PART 3

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Multiplying fortunes and debts (3)

Test your knowledge.

-3x2

(-3)(7)

(-6)(-2)

-6x+2

(-5)x3

-5x-2

-5(4)

-5x-4

Your score is

IS THERE A DIFFERENCE BETWEEN...

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Watch this Khan Academy video and answer the questions. 

All Khan Academy content is available for free at www.khanacademy.org.

WHAT IS A POWER?

-62 ≠(-6)2 but -63 = (-6)3 Why?

Video from mathwithmrbarnes on YouTube. 

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Powers - true or false?

Test your knowledge.

(-4)2 =-42

(-2)2 =-22

(-3)4 =-32

(-8)5 =-82

Your score is

EXPAND AND SIMPLIFY

(x-2)2 = (2-x)2 but (x-2)3 ≠ (2-x)3 Why?
Video from The Cowan Academy on YouTube.

Expand a biNomial raised to the 3 power

(x+2)3
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Expand a binomial raised to the 3 power - true or false?

Test your knowledge.

(x-3)3 =(3-x)3

(x-4)2 =(4-x)2

(x-3)2 =(3-x)2

(x-4)3 =(4-x)3

Your score is

negative and minus on a calculator

The difference between negative and minus on a TI84 calculator - special keys.
Video from mcstutoring on YouTube.
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Try the following on your calculator and select the correct answer.

15 minus negative 2 plus 8

27 plus negative 4 minus negative 3

7 minus 7

7 minus -7

8 minus negative 8 minus 4

Your score is