Prime/ Composite
How many composite numbers are there between 10 and 20?
7
Which operations should be performed first when simplifying an expression using MDAS?
Multiplication
What happens when you add two odd numbers together?
The sum is always an even number.
Is 714 divisible by 3? Why?
Yes, because its sum is 12 and 12 is divisible by 3.
What is an odd number?
An odd number is a whole number that cannot be divided exactly into two equal whole numbers.
How many prime numbers are there between 15 and 25?
3
Evaluate the following using MDAS Rule:
4+5x6
34
I am thinking of a 3-consecutive-digit number. The sum of its digits is even, but the number itself is odd. What is the possible number?
123, 321, 345, 543, 567, 765, 789, 987
What is the Divisibility Rule for 2,5 and 10?
For number 2, it ends with even numbers.
For number 5, it ends with 5 and 0.
For number 10, it ends with 0.
What is an even number?
An even number is a whole number that can be divided exactly by 2 with no remainder.
A school has lockers numbered 1 to 20. A student is told that their locker number is composite, it is greater than 10, and has three factors. What is their locker number?
16
Solve the following using MDAS Rule:
10-6-:2 +3
10
Is 2,438 divisible by 6? Why?
No, because it is only divisible by 2 but not by 3.
What are prime numbers?
A prime number is a whole number greater than 1 that has only one factor, itself and the number one.
Is it possible to express the composite 100 as the sum of two prime numbers? If yes, what is the possible pair?
Yes, one possible pair is 3 and 97.
Other pairs are: 11 and 89, 17 and 83, 29 and 71, 41 and 59, 47 and 53
Solve the following using MDAS:
18-: 2x3-5
22
Is 8,172 divisible by 9? Why?
Yes, because its sum is 18 and 18 is divisible by 9.
What is the difference between Prime and Composite numbers?
The difference between a prime and a composite number is the total number of factors each number has.
If you take any prime number greater than 3, square it, and then divide the result by 24, what will the remainder always be?
1
What is the answer to the following expression?
80-45-:5x3+12x4-:2
77
How many odd numbers are there between 0 and 10?
5
4,560 is divisible by what numbers?
2,3,5,6 and 10
Divisible means?
A number is capable of being divided equally without remainder.