Subtraction

Important Notions

The number being subtracted from is usually called the minuend, the number being subtracted the subtrahend.

The term "minuend - subtrahend" is called the difference between these two numbers. The final result is also known as the value of the difference .

Example

Paula gives 3 of her 8 marbles to her friend Sarah. Then 5 marbles remain in Paula's possession.

$8-3=58\; -\; 3\; =\; 5$

Written Subtraction

To subtract in a written form, you must write minuend and subtrahend one below the other and then subtract starting from the ones place.

If the digit of the subtrahend is larger than the one of the minuend (e.g., if you calculate $2-32-3$), then the result will be negative. There are two methods what do do in this situation:

Splitting method

1. Subtract the "ones": $7-5=27-5=2$

2. Subtract the "tens". Since $22$ is less than $33$, you take one 100 and split it into 10 tens. So there are $1212$ tens from which you can now subtract $33$: $12-3=912-3=9$.

3. Subtract the "hundreds": $4-1=34-1=3$

Completion method

1. Subtract the "ones": $7-5=27-5=2$

2. Subtract the "tens". Since $22$ is less than $33$, you "complete" it to $1212$ and calculate $12-3=912-3\backslash \; =\backslash \; 9$. To "memorize" the completion, you note a $11$ at the hundreds digit, which is later subtracted.

3. Subtract the "hundreds": $5-(1+1)=5-2=35-(1+1)=5-2=3$

Besondere Subtraktionen

• Brüche subtrahieren

• Vektoren subtrahieren