Count the cubes in the picture and round them to the nearest ten. 

If the number of cubes ends with a number less than 5, then the number of tens remains the same, and the number of ones changes to zero. 

If the number of ones is equal or greater than 5, we increase the number of tens by 1, and write 0 in ones place.

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To round a number means to count to its nearest ten. When rounding, the exact number of objects doesn’t matter. We say the approximate number, which is easy to remember. For example, we can more easily remember 40 than 43.

Each number has two nearest tens, one of which is less than this number, and the other is greater. Let’s consider number 15. In the number line it is placed between 10 and 20. So, we can round it down to 10, which is less than 15, or round up to 20 - which is greater. 

How can we identify if to round up or down? Just check what way we will count faster. For example, there is only one count from 59 to 60.

And counting to 50 will take much more time: 58, 57, 56, 55, 54, 53, 52, 51, 50.

Thus, we will round 59 to 60.

And what about the number 43? It is easier to count from 43 to 40 than to 50, so we round it to 40.  

There is a general rule for rounding. Look at the ones place in the number. If there are less than 5 ones, then we round the number down. If there are more than 5 ones, we round it up towards a greater number. 

Let’s count the cubes and round the number. 

We can see cubes arranged in 5 groups of 10s. There are also some separate cubes. Their number is 4, that is less than 10.

According to the rule, we round numbers between 5-9 up to ten. And if we have numbers 4 and less, we round them down to zero. We can see it in the example of cubes. If you miss 2 items to complete the column of ten cubes, you or your mommy may find them under the sofa or in the kitchen. So, we can consider this column full.  

But if there are 4 of 10 cubes left, there are small chances to find 6 cubes, so we may imagine we do not have this column.  

Let's write the number of tens in tens place, and the number of ones in ones place. 

We got the number 54. Let's round it. The first digit on the right is the number 4. It is less than 5. As it is difficult to find 6 missing cubes to complete the set of 10 items, we round the number of ones down to 0.

Thus, we get 5 tens and 0 ones.

Let’s count and round the number of cubes shown below. 

There are 6 columns with 10 items in each, and 5 separate cubes. These are 6 tens and 5 ones. The number of ones is 5. We can easily add 5 to get the next ten. Therefore, we round 5 to 10 and get 1 additional ten, which we add to the existing 6 tens. 

Thus, we get 7 tens and 0 ones.

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