Use Place Value to Solve Problems

In this activity, we need to use our place value knowledge to solve problems. 

 

We need to understand how we can add on tens. 

 

We know how to count in tens:

10, 20, 30, 40, 50, 60, 70, 80, 90, 100

 

But what happens when the ones digit is not 0?

Let's look at 54 in a place value chart:

 

Tens	Ones
5	4

 

Here we have 5 tens and 4 ones. So what happens if we add 10 to this number?

We need to add one ten onto 5 tens and the ones will just stay the same as we are not adding on any ones:

 

Tens	Ones
6	4

 

This gives us 64. Now let's continue the pattern of adding on tens to 54:

54, 64, 74, 84, 94. 

So, when we add ten to any number, the tens digit will go up and the ones digit will always stay the same. 

 

Example

The pirate is travelling across these islands. 

He needs to add on ten each time to complete the pattern. 

What are the missing numbers?

 

  

If we count on ten from 21 we need to add on 1 ten and the ones number will stay the same.  

21 + 10 = 31

 

Then, we need to add on another 10 to 31:

31 + 10 = 41 

 

This gives us the pattern: 21, 31, 41, 51 

 

So our missing numbers were 31 and 41. 

 

How do you feel about trying some questions on this now?