Contributor: Ashley Nail Murphy. Lesson ID: 14111
Ready for a race? It doesn't matter how you get to the finish line! With these subtraction strategies, you will always win.
Imagine you and your friends are running a race! Everyone stands at the starting line. A parent yells, “Ready? Set. Go!”
As you dash toward the finish line, you notice something exciting.
One friend zooms by like a cheetah. Another waddles like a penguin. One friend hops like a frog, and another even crawls like a cat!
You all cross the finish line, but everyone does it in different ways!
Just like in this race, subtraction problems can be tackled in many different ways!
No matter how you do it, you'll always reach the same answer at the finish line!
There are so many different ways to subtract!
Solve the same subtraction problem in four different ways.
12 - 5 = ____
See how each method is different but still gets you the same answer!
Method 1: Draw a Picture
Start with the big number: 12.
Draw 12 objects, like stars!
Now, subtract the smaller number. Cross out 5 stars in your picture.
Count how many stars are left. This is your answer!
12 - 5 = 7
Method 2: Use a Number Line
Draw a number line and mark the numbers 0 to 20.
Start at the big number: 12. Draw a dot at 12.
Hop backward the amount you are subtracting. You are subtracting 5, so make 5 hops backward.
Your hops ended at 7!
12 - 5 = 7
Method 3: Use Ten
Break the number into easier pieces!
12 can be split into 10 and 2. You can use a ten frame to help you.
Show the number 12 in a ten frame. The ten frame is full, with 2 more cubes outside.
Now, take away 5. First, take away 2 to make 10.
You still need to subtract more. Take away 3 more from the ten frame.
Count how many cubes are left in the ten frame. There are 7 cubes left!
12 - 5 = 7
Method 4: Think Addition
Addition can help you solve subtraction!
Turn the subtraction problem into an addition problem.
12 - 5 = ____ becomes 5 + ____ = 12
5 + 7 = 12
Now, turn it back into a subtraction problem.
12 - 5 = 7
You just solved a subtraction problem in different ways. Each method gives you the same answer.
Some ways may be faster. Other ways may be more fun — just like your race with your friends!
Run over to the Got It? section to practice!