Learn
Subtraction is taking a group away from a bigger group.
The addition symbol is the minus (-) sign.
The answer to a subtraction problem is the difference.
The order of the subtraction problem matters
How to Subtract
To subtract, you count backwards from the first number.
Example:
9 - 4 = ?
9 - 1 = (8)
9 - 2 = (7)
9 - 3 = (6)
9 - 4 = (5)
9 - 4 = 9
Using Pictures
A helpful tool when subtracting is drawing pictures.
Pretend like your teacher just gave you 5 apples. Your friend, Luca, asked you for 3. If you give him apples, how many would you have left?
Lets first start off by drawing five apples:
Next, crossout 3 of the apples:
Now you can easily count how many apples you would have left:
Subtracting Numbers Greater than 10
To subtract numbers greater than 10, first subtract the ones, then work your way towards the greater place values.
Example:
19 - 7 = ?
First subtract 7 from 9:
19
- 7
2
Then subtract the 10s:
Since the value of the 10s digit in the second number is zero, you will subtract 0 from 1.
19
- 7
12
The difference of 19 and 7 is 12.
If second number in the ones place is greater than the first number, then you will have to "borrow" from the tens place.