Wikijunior:Introduction to Mathematics/Negative Numbers

Adding and Subtracting
~ a positive number

~ a negative number



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.
 * $$-2\times3=-6$$
 * $$2\times-3=-6$$

Multiplying a negative number by a negative number makes the answer positive.
 * $$-2\times-3=6$$

Do the same for dividing.
 * $$-6\div3=-2$$
 * $$6\div-3=-2$$
 * $$-6\div-3=2$$

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