What you need to know

Things to remember:

  • When counting forwards or backwards in 10s, 100s, 1000s, or 10000, this is the same as adding or subtracting this amount.

We get powers of 10 by starting with 1 and multiply by 10.

1\times10=10

10\times10=100

100\times10=1000

1000\times10=10000

So, our powers of 10 are: 1, 10, 100, 1000, 10000…

Let’s start by adding 10s to 2135

2135

2135+10=2145

2145+10=2155

2155+10=2165

And we can create a sequence; 2135, 2145, 2155, 2165…

Looking at the sequence we can see that the next number will be 2175.

What is the next number in the sequence?

3400, 3500, 3600, 3700, …

First, we have to see how much our sequence is changing by. If we choose two numbers next to each other, we can see that we’re adding 100 each time.

3400

3400+100=3500

3500+100=3600

3600+100=3700

To find the next number in the sequence, we have to add 100 to the last number.

3700+100=3800

The next number in the sequence is 3800.

What is the next number in the sequence?

9780, 8780, 7780, 6780, …

First, we have to see how much our sequence is changing by. If we choose two numbers next to each other, we can see that we’re subtracting 1000 each time.

9780

9780-1000=8780

8780-1000=7780

7780-1000=6780

To find the next number we have to subtract 1000 from the last number.

6780-1000=5780

So, the next number in the sequence will be 5780.

Example Questions

Question 1: What is the next number in the sequence?

 

7430, 7420, 7410, 7400, …

 

Answer

First, we have to see how much our sequence is changing by. If we choose two numbers next to each other, we can see that we’re subtracting 10 each time.

 

7430

 

7430 +10=7420

 

7420+10=7410

 

7410+10=7400

 

To find the next number we have to subtract 10 from the last number.

 

7400-10=7390

 

So, the next number in the sequence will be 7390.

 

Question 2: What is the next number in the sequence?

 

2500, 3500, 4500, 5500, …

 

Answer

First, we have to see how much our sequence is changing by. If we choose two numbers next to each other, we can see that we’re adding 1000 each time.

 

2500

 

2500 +1000=3500

 

3500+1000=4500

 

4500 +1000=5500

 

To find the next number we have to add 1000 to the last number.

 

5500-1000=6500

 

So, the next number in the sequence will be 6500.