Finding the Missing Numbers in Subtraction will assist us to learn the fundamental Subtraction Facts and their Relationship to Addition. This concept can lay a stronger basis to learn the algebra introduction as you can replace the missing number with a variable or letter.
Usually, we would recommend you to be thorough with the Basic Subtraction Facts as a prerequisite for becoming pro in the concept of Missing Numbers in Subtraction. Now go through the entire article, to know how to find the missing numbers in subtraction as well as various cases included in it.
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How to Fill the Missing Numbers in Subtraction?
Here we will discuss in detail the typical questions we encounter in primary school maths with three numbers in a sentence. In these kinds of subtraction problems, the larger number will be present at the beginning of the subtraction, take away the smaller number. This will be equal to another number that is smaller than the first.
Here is the list of three cases that we face during missing number problems.
(i)10 – 5= …….
Larger number subtract the smaller number
(ii)10- ……= 5
Subtract the other smaller number from the larger number to obtain the missing number.
(iii)…….-5=5
Add the two other numbers to get the missing number.
Cases in Missing Digits Subtraction
There are three different cases that we commonly encounter while dealing with the Missing Numbers Subtraction Problems. They are as follows
- If the Missing Number is next to the equal to sign subtract the second number from the first.
- If the Missing Number is being subtracted from a larger number subtract the given result from the larger number.
- If at all the missing number is right before the subtraction sign then add the numbers together.
This is a quick guide on how to deal with missing number subtraction problems. However, you need to understand why this works and how to apply it.
Solving Subtraction Problems with Missing Digits
Example 1.
What number must be taken away from 9 to get a result of 5?
9-…….=5?
Solution:
This is the case of having a larger number at the beginning. So, simply we will subtract the other smaller number from the larger number.
9-5 =4
Therefore, you need to take away 4 from 9 to obtain the result 5 i.e. 9-4=5
Example 2.
From what number must you subtract 2 to leave a result 3?
?– 2 =3
Solution:
This is the case in which the missing digit is right before the subtraction sign then add the numbers together.
2+3 = 5
Therefore, you must subtract 2 from 5 to get 3 i.e. 5-2=3
Example 3.
What is the result when you subtract 4 from 8
8-4=….?…..
Solution:
This is the most common case that is a missing digit is present next to the equal sign. You just need to subtract the second number from the first.
8-4=4
Therefore, 8-4=4.
Example 4.
From what number you must subtract 8 to leave 2?
……-8=2
Solution:
This is the scenario in which the missing digit is placed before the subtraction sign. You simply need to add the two numbers to obtain the missing digit.
8+2 =10
Therefore, you must subtract 8 from 10 to leave 2.