## INTEGERS - ESSENTIAL POINTS

• Integers are just like whole numbers, but they also include negative numbers. For example {...-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6 ...}
• Like whole numbers, integers don't include fractions or decimals.
• The integers may be negative or positive
• We need negative integers to denote the withdrawl of amount from bank, minus temperatures in areas like arctic pole, loss in business
• The numbers like 90, 25, 46 are positive integers, whereas the numbers like – 43, - 29, - 78 are negative integers.
• The sign of positive is not put before the positive integer.
• When two or more positive integers are added or multiplied we get a positive integer. For instance the number 23 and 45 are added the answer is 68. When both are multiplied, the answer is 1035.
• When two or more negative integers are added we get a negative integer. For instance (-25) + ( - 15) = -40
• But when two negative integers are multiplied, we get a positive integer. For example (-25) X (-15) = 375
• When one positive and one negative integer are added, we subtract them and put the sign of bigger integer. For instance (50) + (-76) = -26
• The positive integer is greater than the negative integer.
• If in a competitive exam the 3 marks are awarded for every correct answer and – 2 are awarded for every incorrect answer, then if Karamveer, anwers 70 questions correctly and 30 questions incorrectly, then the marks scored by Karamveer are:
1. Marks gained = 70 X 3 = 210
2. Marks lost = 30 X 2 = 60
3. Total marks scored are 210 – 60 = 150 marks.
• The greatest negative integer is – 1 and the smallest positive integer is 1.