easy way to understand sign use in addition and subtraction in Hindi and Urdu

easy way to understand sign used in addition and subtraction  Hindi and Urdu

دو الگ الگ سائن مائنس ھو تا ھے

دو ایک جیسے سائن پلس ھوتا ھے

दो अलग-अलग मंत्रालय हैं

दो समान संकेत प्लस

do alag-alag mantraalay hain

do samaan sanket plas

Numbers Can be Positive or Negative

This is the Number Line:

Negative Numbers (−)	Positive Numbers (+)

"−" is the negative sign.	"+" is the positive sign

No Sign Means Positive

If a number has no sign it usually means that it is a positive number.

Example: 5 is really +5

Balloons and Weights

Let us think about numbers as balloons (positive) and weights (negative):

This basket has balloons and weights tied to it: The balloons pull up (positive) And the weights drag down (negative)

Adding a Positive Number

Adding positive numbers is just a simple addition.

We can add balloons (we are adding positive value) the basket gets pulled upwards (positive)

Example: 2 + 3 = 5

is really saying

"Positive 2 plus Positive 3 equals Positive 5"

We could write it as (+2) + (+3) = (+5)

Subtracting A Positive Number

Subtracting positive numbers is just simple subtraction.

We can take away balloons (we are subtracting positive value) the basket gets pulled downwards (negative)

Example: 6 − 3 = 3

is really saying

"Positive 6 minus Positive 3 equals Positive 3"

We could write it as (+6) − (+3) = (+3)

Adding A Negative Number

Now let's see what adding and subtracting negative numbers looks like:

We can add weights (we are adding negative values) the basket gets pulled downwards (negative)

Example: 6 + (−3) = 3

is really saying

"Positive 6 plus Negative 3 equals Positive 3"

 

We could write it as (+6) + (−3) = (+3)

The last two examples showed us that taking away balloons (subtracting a positive) or adding weights (adding a negative) both make the basket go down.

So these have the same result:

• (+6) − (+3) = (+3)
• (+6) + (−3) = (+3)

In other words subtracting a positive is the same as adding a negative.

Subtracting A Negative Number

the basket gets pulled upwards (positive)

Lastly, we can take away weights (we are subtracting negative values)

Example: What is 6 − (−3) ?

6−(−3) = 6 + 3 = 9

Yes indeed! Subtracting a negative is the same as adding!

Two Negatives Make a Positive

What Did We Find?

Adding a positive number is simple addition ...

Adding a Positive is Addition

 

Positive and Negative Together ...

Subtracting a Positive
or
Adding a Negative
is
Subtraction

Example: What is 6 − (+3)?

6−(+3) = 6 − 3 = 3

Example: What is 5 + (−7)?

5+(−7) = 5 − 7 = −2

 

Subtracting a negative ...

Subtracting a negative is the same as Adding

Example: What is 14 − (−4)?

14−(−4) = 14 + 4 = 18

The Rules:

It can all be put into two rules:

	Rule				Example
+(+)	Two like signs become a positive sign				3+(+2) = 3 + 2 = 5
−(−)					6−(−3) = 6 + 3 = 9
+(−)	Two, unlike signs, become a negative sign				7+(−2) = 7 − 2 = 5
−(+)					8−(+2) = 8 − 2 = 6

They are "like signs" when they are like each other (in other words: the same).

 

So, all you have to remember is:

Two like signs become a positive sign

Two, unlike signs, become a negative sign

Example: What is 5+(−2)?

+(−) are unlike signs (they are not the same), so they become a negative sign.

5+(−2) = 5 − 2 = 3

Example: What is 25−(−4)?

−(−) are like signs, so they become a positive sign.

25−(−4) = 25+4 = 29

Example: What is −6+(+3)?

+(+) are like signs, so they become a positive sign.

−6+(+3) = −6 + 3 = −3

Start at −6 on the number line, move forward 3, and you end up at −3

Now Play With It!

Try playing Casey Runner, you need to know the rules of positive and negative to succeed!

 

A Common Sense Explanation

And there is a "common sense" explanation:

If I say "Eat!" I am encouraging you to eat (positive)

If I say "Do not eat!" I am saying the opposite (negative).

Now if I say "Do NOT eat!", I am saying I don't want you to starve, so I am back to saying "Eat!" (positive).

So, two negatives make a positive, and if that satisfies you, then you are done!

 

Another Common Sense Explanation

A friend is +, an enemy is −

+ + ⇒ +		a friend of a friend is my friend
+ − ⇒ −		a friend of an enemy is my enemy
− + ⇒ −		an enemy of a friend is my enemy
− − ⇒ +		an enemy of an enemy is my friend

A Bank Example

Example: Last year the bank subtracted $10 from your account by mistake, and they want to fix it.

So the bank must take away a negative $10.

Let's say your current balance is $80, so you will then have:

$80−(−$10) = $80 + $10 = $90

So you get $10 more in your account.

A Long Example You Might Like

Ally's Points

"If you are nice we will add 3 points (+3). Ally can be naughty or nice. So Ally's parents have said

If you are naughty, we take away 3 points (−3).
When you reach 30 points you get a toy."

 

Ally starts the day with 9 Points:		9
Ally's Mom discovers spilled milk:		9 − 3 = 6
Then Dad confesses he spilled the milk and writes "undo". How do we "undo" a minus 3? We add 3 back again!
So Mom calculates:		6 − (−3) = 6 + 3 = 9

So when we subtract a negative, we gain points
(i.e. the same as adding points).

So Subtracting a Negative is the same as Adding

 

A few days later. Ally has 12 points.
Mom adds 3 points because Ally's room is clean.		12 + 3 = 15
Dad says "I cleaned that room" and writes "undo" on the chart. Mom calculates:		15 − (+3) = 12
Dad sees Ally brushing the dog. Writes "+3" on the chart. Mom calculates:		12 + (+3) = 15
Ally throws a stone against the window. Dad writes "−3" on the chart. Mom calculates:		15 + (−3) = 12

See: both "15 − (+3)" and "15 + (−3)" result in 12.

So:

It doesn't matter if you subtract positive points
or add negative points,
you still end up losing points.

So Subtracting a Positive
or
Adding a Negative
is
Subtraction