Number Support

Question 1

What is a prime number?

Answer 1

A prime number has exactly two factors, 1 and itself.

Question 2

Prime numbers less than 30 are

Answer 2

2, 3, 5, 7, 11, 13, 17, 19, 23 and 29

Question 3

What is a square number?

Answer 3

A whole number, when multiplied by itself, gives a square number.

Example: 4 x 4 = 16

Question 4

First 12 square numbers are

Answer 4

1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144

Question 5

What is a triangular number?

Answer 5

The triangular numbers can be represented as triangles.

Question 6

What is a factor?

Answer 6

If one whole number is divisible by another number, then the second number is a factor of the first number.

Question 7

What is divisibility?

Answer 7

One whole number is divisible by another if, after dividing, the remainder is zero.

Since 18 is divisible by 9, 9 is a factor of 18.

Question 8

A number is divisable by 2 if

Answer 8

the number is an even number

Question 9

A number is divisible by 3 if

Answer 9

the sum of its digits is divisible by 3

Example: 198 is divisible by 3 since 1 + 9 + 8 = 18 is divisible by 3.

Question 10

A number is divisible by 4 if

Answer 10

the last two digits are divisible by 4

Exmaple: 248 is divisible by 4 because 48 is divisible by 4.

Question 11

A number is divisible by 5 if

Answer 11

the last digit is either 0 or 5

Question 12

A number is divisible by 6 if

Answer 12

it is divisible by both 2 and 3

Question 13

A number is divisible by 7 if

Answer 13

you double the last digit and subtract it from the rest of the number and the answer is 0 or divisible by 7

Note: you can apply this rule to that answer again

Example: 672, 2 x 2 = 4, 67 - 4 = 63 which is divisible by 7

905, 5 x 2 = 10, 90 -10 = 80 which is not divisible by 7

Question 14

A number is divisible by 8 if

Answer 14

the number formed by the last three digits is divisible by 8.

Example: 7,120 is divisible by 8 since 120 is divisible by 8.

Question 15

A number is divisible by 9 if

Answer 15

the sum of the digits is divisible by 9.

Example: 549 is divisible by 9 since the sum of the digits is 18 (5+4+9=18), and 18 is divisible by 9.

Question 16

A number is divisible by 10 if

Answer 16

if the last digit is 0.

Question 17

A number is divisible by 11 if

Answer 17

you add and subtract digits in an alternating pattern (add 1st, subtract2nd, add third so on). Then the answer must be 0 or 11

Example: 1364 (1-3+6-4 = 0), hence divisible by 11

913 (9-1+3 = 11), hence divisible by 11

3729 (3-7-2-9 = -11), hence divisible by 11

987 (9 - 8 - 7 = 8), hence not divisible by 11

Question 18

When a number is divisible by another number then it is also divisible by each of the factors of that number.

True OR False?

Answer 18

True

Example: If a number is divisible by 6 then it is also divisible by 2 and 3

If a number if divisible by 12 then it is also divisible by 2, 3 ,4 , 6

Question 19

What are equivalent fractions?

Answer 19

We find equivalent fractions by multiplying or dividing both the numerator and denominator by same number

Example: 2/3, 4/6, 6/9, 8/12 .. are equivalent fractions.

Question 20

A fraction is in lowest terms if

Answer 20

the numerator and denominator have no commmon factors except 1.

To reduce a fraction to lowest terms (also called its simplest form), divide both the numerator and denominator by the GCD. For example, 2/3 is in lowest form, but 4/6 is not in lowest form (the GCD of 4 and 6 is 2) and 4/6 can be expressed as 2/3.

Question 21

A fraction in which numerator is smaller than denominator is called

Answer 21

Proper Fraction

Example: 3/4

Question 22

A faction in which numerator is larger than denominator is called

Answer 22

an improper fraction

Example: 22/7

Question 23

A number which has whole number and a fraction is called

Answer 23

a mixed number

Example 3 2/5