Wikijunior:Introduction to Mathematics/Negative Numbers

Lesson

Adding and Subtracting

~ a positive number

~ a negative number

Adding Rules

Subtracting Rules

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Adding a negative number is the same as subtracting a positive number.

$7+-4=7-4$

Subtracting a negative number is the same as adding a positive number.

$7--4=7+4$

Multiplying and Dividing

Multiplying a negative number by a positive number, or a positive number by a negative number makes the answer negative.

$-2\times 3=-6$

$2\times -3=-6$

Multiplying a negative number by a negative number makes the answer positive.

$-2\times -3=6$

Do the same for dividing.

$-6\div 3=-2$

$6\div -3=-2$

$-6\div -3=2$

Example Questions

$7-3=4$, $9-2=7$, $10-5=5$, $8-3=5$