Subtraction

What is Subtraction?

• Subtraction is taking one amount away from another to find out how many are left over.
• While Addition is about joining, Subtraction is about separating or taking away.
• The answer to a subtraction problem is called the Difference.

The Parts of a Subtraction Sentence We use two special symbols when we write a subtraction story: 8 - 3 = 5

• The Minus Sign (-): This tells us we are taking something away.
• The Equal Sign (=): This tells us what is left over.
• 8: This is the number we start with (the whole group).
• 3: This is how many we take away.
• 5: This is the Difference.

Ways to Solve Subtraction If you want to find the answer, you can use these "Taking Away" tools:

1. The "Cross Out" Method Draw a group of objects. Use a big 'X' to cross out the ones you are taking away, then count what is left.

• To solve, draw 5 circles. Cross out 2. You have 3 left!

2. Use Your Fingers Hold up the number of fingers you start with. Tuck away (fold down) the fingers you are subtracting. Count how many are still standing up.

3. Count Backwards Put the big number in your brain and count down.

• For , say: "10... 9, 8, 7." The answer is 7!

Key Words for Subtraction When you hear these "secret code" words in a story, it usually means you need to subtract:

• Take away
• Left (How many are left?)
• Remain
• Fewer
• Minus
• Difference

Why Do We Learn This?

• Sharing: To know how many cookies are left if you give some to a friend.
• Shopping: To see how much money you have left after you buy a treat.
• Time: To figure out how many minutes are left until recess!

Lesson Summary

• Subtraction means taking away from a group.
• The minus sign (-) shows we are removing items.
• The result is the Difference.