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When we count numbers from one (1) to infinity i.e. 1, 2, 3, 4, 5….. In mathematics when you put dots at the end it indicates that the numbers continue with no end. Ok such numbers are called 1, 2, 3, 4, 5, 6, 7, 8, 9 …… These numbers are sometimes known as counting numbers and they are represented by N.
(i) Natural numbers on the number line
There is another group of numbers which start from 0, e.g. Whole numbers are the numbers which start from 0, e.g.
(i) Whole numbers on the number line
All natural numbers are whole numbers but not all whole numbers are natural numbers. Arrows in both number lines indicate that numbers continue with no end. These are not only group of numbers in mathematics, others will be discussed later.
Even number is any integer which is exactly divisible by 2, e.g.
Odd number is any integer which is not exactly divisible by 2, e.g. Odd number is an opposite of even number, so if any number isn’t divisible by 2 that number is exactly odd number.
Prime number is any number greater than one (1) that is divisible only by one and itself e.g.
The first four numbers before ten are prime numbers even if they are divisible by 3 and 7 those numbers are
(i) List all even numbers between 10 and 20.
11, 12, 13, 14, 15, 16, 17, 18 and 19
12, 14, 16 and 18. Therefore the answer is
(ii) List all odd numbers between 10 and 20.
11, 12, 13, 14, 15, 16, 17, 18 and 19
11, 13, 15, 17 and 19. Therefore the answer is
(iii) What are the prime numbers between 25 and 34?
26, 27, 28, 29, 31, 32, 33.
27, 29, 31, 33.
Step three, the remaining should be tested if each number is divisible by 3 or 7, and we need the number which is not divisible by any of 3 and 7. Now let’s check it out:-
27 is divisible by 3 (this is not prime number) 29 is not divisible by any of 3 and 7 (this is prime number) 31 is not divisible by any of 3 and 7 (this is prime number) 33 is divisible by 3 (this is not prime number) Therefore we only got two numbers which are not divisible by both 3 and 7, those numbers are 29 and 31 Therefore the answer is (iv) Which number is even and prime?
The number which is even and prime is
(1) What do you understand by: i. Natural and whole numbers ii. Even numbers iii. Odd numbers iv. Prime numbers (2) Write number having 5 in hundreds position, 4 in thousands position, 0 in ones position and 4 in tens position. (3) List all odd numbers between 60 and 70 (4) What are prime numbers between 1 and 20? (5) Write the sum of all even numbers between 100 and 110. (6) List all odd natural numbers up to 10 on the number line. (7) Show prime numbers between 30 and 40 on the number line. (8) State whether the sum of the following is an even or odd i. When adding any two odd numbers ii. When adding any two even numbers iii. When adding any odd number and any even number. (9) Is the product of any two even numbers even or odd? (10) Write down the first six prime numbers.
© Yahyou M. (Math's tutor)
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