Identify these questions

What happens when you see a particular question and you’re absolutely stumped?

You can’t see an obvious pattern with any of the 4 operators and exponentials or surds?

There’s another type of tricky pattern and that’s ‘stand-in’ numbers. They’re also called ‘constants’ or ‘dummy’ numbers.

The purpose of questions that contain ‘stand-in’ characters is to test whether you can identify them and then exclude them in your pattern calculation.

This question has ‘stand-in’ numbers. Can you see them?

What is the next number in this series?

2, 4, 2, 8, 2, 12, 2, ?

A 2 B 12 C 14 D 16

Now that you know about questions with ‘stand-in’ numbers that are there to trick you, let’s see how to find the underlying pattern and solve them.

The strategy to answer these questions

To answer these questions, you will be required to:

1. Identify the relationship (this relationship or pattern will hold true for all the numbers) between the numbers, and,
2. Use that relationship to find the missing number or the grouped number set.

Here are rules to uncovering the pattern when there are ‘stand-in’ numbers:

• Numbers may look like they’re part of another pattern but a giveaway is to look for the same repeating number at a regular interval.
• Low value numbers or numbers that look like they’re part of the calculation tend to be used as ‘stand-in’ numbers
• ‘Stand in’ numbers can also be an individual ‘character’ of a larger group of numbers – remember, we need to see characters individually. What’s the ‘stand-in’ number in this series? 108, 228, 348, 468, 588. It’s the last 8, the first 2 characters follow a pattern of an addition of 12.
  

Example Question/s

Watch video for explanation of the following question/s:

What is the next number in this series?

2, 5, 2, 7, 2, 9, ?

A 2 B 10 C 11 D 16

What is the next number in this series?

0108, 0158, 0208, 0258, 0308, 0358, ?

A 0368 B 0408 C 0458 D 0500

Key Rules to remember

• Look for the same repeating number at a regular interval.
• Look for the same repeating character at the same position (e.g. the repetition of 0 at the beginning of 012, 013, 014 etc...)
• Generally, you should exclude ‘stand-in’ numbers from your pattern calculation.

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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