my maths revison guide questions

Prime numbers

How do we write a number as a product of its prime factors?

WORKED EXAMPLE:

Write 24 as a product of its prime factors

Write 36 as a product of its prime factors.

Factors

What are the factors of 40?

Multiples

List the first 4 multiples of 6

What is the  5th  multiple of  {3}

Common Factors

Factorise 24a + 16

What are the common factors of 20 and 25?

Common Multiples

A lighthouse flashes every 6 seconds, another lighthouse signals every 10 seconds. They start by signalling together, when will they next flash at the same time?

What is the LCM of 6 and 10?

Find the highest common factor of 20 and 30 by following the steps below:

What are the factors of 20?

What are the factors of 30?

What is the highest common factor of 20 and 30?

BIDMAS

What is 4 + 2 × 3?

What is 9 - 4 + 3?

a)  4 × 5 - 3 × 2

b) (2 + 3) × (5 - 1)

c) 2 + 6 ÷ 2

d) 8 - (6 - 1)

e) 3 × (4 + 2)

HCF using prime factorisation

For example, suppose you want to find the GCF of 28, 42, and 70. Step 1 says to list the prime factors of each number. Step 2 says to circle every prime factor that’s common to all three numbers:

Find the highest common factor of 14 and 12 by following the steps below:

What are the factors of 14?

What are the factors of 12?

What is the highest common factor of 14 and 12?

LCM using prime factorisation

Jenny wishes to advertise her business, so she gives packs of 4 red flyers to each restaurant owner and sets of 6 blue flyers to each clothing store owner. At the end of the day, Jenny realises that she gave out the same number of red and blue flyers. What is the minimum number of flyers of each colour?

                     flyers

Add/subtract decimals

David is doing some DIY. He buys a 2m length of wood. He needs to cut two pieces of wood - one of length 0.6m and one of length 1.02m.

What is the total length of wood that David needs to cut?

David originally had 2m of wood. What is the length of the piece of wood that is left?

Multiply/Divide decimals

90.5×100=

6.33×100=

0.0047×100=

Simplify a ratio

Write the ratio 40:28 in its simplest form

Share in a ratio

Amit is 12 years old. His brother, Arun, is 9.

Their grandfather gives them…