Maths Shortcuts and Tips

Here are some general rules and terminology that are useful to know for your exam.

Even/Odd Numbers

The below rules are useful to check your result when you do calculations. For example, if you have a calculation with 2 even numbers and all other options presented are odd and one option is even, from these rules, you can see that the even one is going to be the correct answer.

• Even +/- Even = Even
• Even +/- Odd = Odd
• Odd +/- Odd = Even
• Even x Even = Even
• Even x Odd = Even
• Odd x Odd = Odd

Prime numbers are numbers greater than 1 and only divisible by 1 or itself only.

Consecutive numbers are numbers that follow after one another in order.

Factors Factors of 6 are? 2 and 3. For every number, 1 and itself is a factor. So, for 6, a factor of it is also 1 & 6 because 1 x 6 = 6. For 7, it's 1 & 7 because 1 x 7 = 7. 7 is a prime number so it can only be factorised once - by itself and 1.

Multiples - Multiples of 6 are? 12, 18, 24.

Quick Mental Maths

Here are some tips to work through maths calculations quickly:

Adding and subtracting large numbers

Adding numbers like 745 + 852 can be done the traditional way or the quick way. To do the quick way:

1. Round up / round down
2. Add back / take away the difference

Therefore, do 750 + 850 = 1600. Then take away “5” (1595) and add “2” = 1597. Easy right? There are fewer steps and you can work quickly through.

It works in the same way with subtraction, but you take away.

Additionally, if you have very large numbers, you can group them into smaller parts (e.g. 10s) and then work through them part by part.

Know basic subtraction rules

It’s useful to know some basic calculations as it helps with larger calculations:

For example:

7 + 3 = 10, therefore 10 – 3 = 7 or 10 – 7 = 3 and likewise,

70 + 30 = 100, therefore 100 – 30 = 70 or 100 – 70 = 30.

Other calculations you should know are:

• 6 + 4 = 10 or 4 + 6 = 10
• 8 + 2 = 10 or 2 + 8 = 10
• 1 + 9 = 10 or 9 + 1 = 10
• 5 + 5 = 10

See how with just 5 sets of calculations (including 7 + 3) we go through pretty much all numbers from 1 – 10.

Example Question/s

Watch video for explanation of the following question/s:

Which one of the following is a multiple of 2?

A 295 B 459 C 716 D 983

What is a factor of 5?

A 10 B 5 C 2 D 3

What is the result of 5730 – 4537?

A 1207 B 1937 C 907 D 1193

Key Rules to remember

• Know terminology of the following: prime, consecutive, factors, multiple.
• Round-up or round-down and add/take away differences when calculating larger numbers.
• Know rules with odd/even numbers to help make answer selections easier or to verify correct/incorrect answers.

Practice time!

Now, it's your turn to practice.

Click on the button below and start your practice questions. We recommend doing untimed mode first, and then, when you're ready, do timed mode.

Every question has two solutions videos after you complete the question. The first is a quick 60 second video that shows you how our expert answers the question quickly. The second video is a more in-depth 5-steps or less explainer video that shows you the steps to take to answer the question. It's really important that you review the second video because that's where you'll learn additional tips and tricks.

Once you're done with the practice questions, move on to the next checkpoint.

Now, let’s get started on your practice questions.

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