A Quick Review of Integers by Teacher Ramsel

INTEGERS

Integer is any number in the number line which is a whole number not including fraction. It includes 1, 2, 3,… and their opposite signs, -1,-2,-3,… including 0. Integers are signed numbers, negative(-1) and positive (+). When a number; say 2 is given, it is written as +2 or 2, without a sign is considered as positive. A negative number say negative 2 is written as -2.

In other words, the positive integers are the counting numbers,: 1,2,3,… on the right of 0 or at the x –axis in the coordinate system, whereas, the negative integers are those numbers opposite sign. Going to the right of the x-y axes coordinate system indicates positive, going to the left indicates negative. Going up of at the y coordinate indicates positive, and going down of the coordinate axis indicates negative sign.

The x-y Coordinate system

Pic Source: https://magoosh.com/hs/sat/sat-math/sat-math-strategies/2014/coordinate-geometry-basics/

Integers in reality

Positive	Negative
Adding how many	Deducting points
Deposit money in bank	Withdrawing money from bank
Earning money from somewhere	Borrowing money from anywhere
Winning at any case	Losing at any  case
Increasing or Incrementing	Decreasing or devaluating
Going to the east	Going to the west
Going up an elevator	Going down at an elevator
Swimming up from the ocean	Diving into the ocean
Airplane flying up in the sky	Submarine sailing in the deep ocean
Rising of temperature at any time	Freezing of temperature at any time
Standing  taller	Bowing down to sit down

 

 

Operations in Integers: Addition and Subtraction

1. – 4 + 11 = 7
2. – 4 + (+11) = 7
3. 4+11= 15
4. +4 + (+11) = 15
5. -20 + 6 = -14
6. – 50+-13 = – 63
7. -1+ – 99 = – 100
8. 1+99 = 100
9. 37 + -2 = 35
10. -2 + – 3 = – 5

Important Rule to Use:

Adapt the lyrics from the song tune of the song: Row, row your boat:

       Same sign, add and keep,

       Different sign, subtract

       Take the sign of the bigger number

       Then you will be exact

Click on the link below to play:

Subtraction and Addition Rule of Integers

Word Problems:
1. Mr. Mishra deposited 10,000 dollars and withdrew 2000 dollars a week after. How much money remained to his bank account?
Solution: $10000 + ( – 2000) = $8,000 or
$10000 – 2000 = $8,000 remaining amount

2. Pao dives 2 meters down the ocean from a view deck of 5 meters above sea level, then swam a bit level up of a meter. How deep is his current position from the sea level?
Solution: -2 + 5 + 1 = 4 or
5 +(-2) + (1) = 4m

3. Susie borrowed 1 baht today and borrowed 9 baht a day after from her friend. How much money Susie owed in total?
Solution: -1 + -9 = -10 (follow subtraction rule)
4. Susie owed 10 baht from friend and returned 5 baht today, how much does she still owe her friend?
Solution: -10 – (+) 5 = – 5
+ – if the operation is subtraction,
change the subtraction sign to addition
and change sign of the subtrahend, then proceed to addition rule

Have a nice day!