Positive and Negative Numbers
You’re probably familiar with positive numbers—you use them all the time in numbers
that you give other people, like “go buy 3 apples from the store”—they’re everywhere!
You probably know how to add, subtract, multiply, and divide them, and so on. Now,
we’re going to give you more numbers to think about—negative numbers. Negative numbers
are similar to positive numbers when you count them, but they have a minus sign
in front of them, like this: -3. Negative numbers measure how much of something
you don’t have, or how much you lack. It can also measure how much you owe someone,
especially when dealing with money. Negative numbers are used on the coordinate
plane to show direction.
Negative numbers can be counted the same way that regular numbers are counted, you
just have to remember to include “negative” in front of them. For example, when
counting positive numbers, you say “one, two, three, four” etc, so when counting
negative numbers, you would say “negative one, negative two, negative three, negative
four” etc. When writing these numbers, you would simply include a negative (minus)
sign in front of them, so it would look like this: -1, -2, -3, -4.
Thinking about negative numbers gets tricky sometimes, because the higher you count,
the smaller the numbers get. For example, -4 is smaller than -1, even though 4 is
greater than 1 when talking about positive numbers. This is because, on the number
line, -4 is further away from 0 than -1 is. You can picture it like this:
So, the further you count to the left (past zero) the smaller the numbers get, and
the further you count to the right, the bigger they get. This is important to remember
because you’ll have to
compare negative numbers sometimes, so you need to know which number is
bigger and which is smaller.
subtracting positive and negative numbers can also be a challenge, because
you have to pay close attention to the signs (+, -) in front of the numbers.
dividing positive and negative numbers is challenging, but you can do
it if you follow the rules for negative numbers.