Why Do We Add and Subtract?
People have been adding and subtracting for a very, very long time! Long ago, people needed to count things like sheep, fish, and apples. They wanted to know how many they had when they got more, or how many were left when some went away.
Today, you get to learn all the cool ways to show adding and taking away. You can use objects, your fingers, drawings, sounds, acting, words, and even write number sentences!
Big Ideas About Addition and Subtraction
Before we start, let's learn some important words. Addition means putting things together to get more. Subtraction means taking things away to get less. We can show these ideas in many different ways!
Addition = Putting Together
Subtraction = Taking Away
Many Ways to Show It
The Plus and Minus Signs
See Addition and Subtraction
Let's look at a picture that shows how addition works. We start with one group, add another group, and get a bigger group!
Look at the picture above. The blue circles show the first group of 2 apples. The purple circles show the second group of 3 apples. When we push them together, we count all of them and get 5. The number sentence at the bottom says 2 + 3 = 5.
Number Sentences for Adding and Subtracting
A number sentence (also called an equation) is a way to write adding or subtracting with numbers and symbols. Let's look at how they work!
Remember: the plus sign (+) tells you to add. The minus sign (−) tells you to take away. The equals sign (=) tells you the answer comes next!
Many Ways to Represent Addition and Subtraction
One of the coolest things about math is that you can show the same problem in lots of different ways. Let's look at all the ways you can represent (that means "show") addition and subtraction.
Look at all seven boxes in the picture. Each one shows the same problem — 2 + 3 = 5 — but in a different way! You can pick the way that makes the most sense to you. Some kids like using their fingers. Some like drawing. Some like acting it out. They are all correct!
Let's Solve a Problem Together!
Let's practice with a fun story problem. We will show the answer in different ways!
Which Way Works Best?
Each way of showing addition and subtraction is helpful. Some ways are better in certain situations. Let's compare them!
| Way to Show It | When It's Great | Watch Out For |
|---|---|---|
| Fingers | Quick and easy! You always have your fingers with you. | Hard for numbers bigger than 10. |
| Objects | You can touch and move them. Great for understanding! | You need to have objects nearby. |
| Drawings | You can see your thinking on paper. Works for any number! | Takes a little more time. |
| Sounds (claps) | Fun and active! Great for learning with your body. | Can be tricky to keep track. |
| Number Sentences | Fast and neat. This is how grown-ups write math! | You need to know the symbols + − =. |
Getting Ready for Bigger Math
Right now you are learning to add and subtract with small numbers (up to 10). As you keep learning, you will use these same ideas with bigger numbers! Let's see how what you are learning now connects to what comes next.
| What You Are Learning Now | What Comes Next |
|---|---|
| Adding and subtracting within 5 | Adding and subtracting within 10, then 20! |
| Using objects and fingers to count | Using mental math (solving in your head!) |
| Writing number sentences like 3 + 2 = 5 | Solving problems with missing numbers like 3 + __ = 5 |
| Drawing pictures to show math | Using number lines and charts |
Everything you learn now is like building blocks. Each new skill stacks on top of what you already know. Keep practicing, and soon adding and subtracting will feel as easy as counting to 10!
Practice Problems
Now it is your turn! Try these problems. You can use any way you like — fingers, drawings, objects, or number sentences.
Let's Remember What We Learned!
Addition means putting groups together to make more. Subtraction means taking away from a group to make less. You can show both of these in many ways: using objects (like blocks or counters), fingers, drawings, sounds like clapping, acting out situations, verbal explanations, or number sentences (equations).
The plus sign (+) means add or put together. The minus sign (−) means subtract or take away. The equals sign (=) shows the answer. Every way of showing addition and subtraction is a good way. Pick the one that helps you understand, and keep practicing!