What are the multiples of 10?
The multiples of 10 are numbers that end with one or more zeros. For example, 10, 20, 30, 40,… 100.
What do you understand by the phrase “subtraction by tens”?
When we subtract a number by any multiple of 10, the number obtained is simply the tens place values. Have a look at this example with the multiples of 10.
Therefore, while subtracting any number with 10 or the multiples of 10, only the tens place will change.
Give an example of subtracting by ten.
Let us take the following equation as an example: 53 – 10 = ? Here, the minuend is 53 and the subtrahend is 10. As you can see, the subtrahend is a multiple of 10 and has nothing in its ones place.
So, we will subtract by arranging the numbers as per their place values.
Have a look at the tens digits. We have 5 tens and 1 ten. When we subtract them, we get 5 – 1 = 4. We can write this as 5 tens – 1 ten = 4 tens.
Since the ones place for 10 has nothing, the 3 ones automatically come down, as zero subtracted from any number results in the number itself.
Thus, by subtracting 10 from 53, we get 43 as the answer.
Solved Examples on Subtraction to 10
1) Solve: 60 – 30 = ___
Answer: Here, let us have a look at the place values of the digits.
Tens | Ones |
|---|---|
6 | 0 |
3 | 0 |
As we can see from the tens digits, 6 – 3 = 3, so 6 tens – 3 tens = 3 tens.
3 tens is 30.
Hence, 60 – 30 = 30
30 is the answer.
2) Find 70 – 20 on the number line.
Answer:
In order to find 70 – 20 = ___, let us prepare an open number line. An open number line is like a usual number line without any numbers. You can place the numbers as per your choice.
In this open number line, we start at 70, the minute. Now, for subtraction, we have to move to the left of the number line. Here, 20 is just 2 tens. So, we have to count back by 2 tens to get the answer.
From the above number line, you can see that on counting back by 2 tens, we will arrive at 50 on the number line.
Thus, 70 – 20 = 50
3) Using addition to subtract, find the answer to 80 – 30.
Answer:
Let us have a look at the number line where we begin at 30, the subtrahend.
Now, imagine that 30 + ___ = 80, or 30 added to a number gives us 80.
Here, we have 3 tens, and in order to reach 8 tens, we will have to skip count from 30 to 80. We will count on by the tens to reach 80. That will give us 30 + 50 = 80.
So the answer is, 80 – 30 = 50.
4) Michael bought 50 coloring books. He gave 20 coloring books to his sister, Jenny. How many coloring books does Michael have now?
Answer:
As per the problem, the number of coloring books bought by Michael = 50
Number of coloring books Michael gave to Jenny = 20
Imagine, 20 + ___ = 50, which is a number added to 20 results in 50.
Now, we must begin at 20 on the number line.
We will count on by tens on the number line to reach 50.
That will give us 20 + 30 = 50.
Now that we have used addition to subtract tens, we can find the answer to 50 – 20 which is equal to 30.
Michael gave 30 coloring books to his sister, Jenny.
We should always keep in mind that 10 ones make 1 tens and 1 tens is formed by 10 ones. This is also called regrouping.
1 ten = 10 ones