Subtract by Counting On - Up to 20
π§ββοΈ Climb the ladder! Sometimes the fastest way to subtract is to actually add. When two numbers are close together, just count up!
Do this: Read the concept below, then try the quiz or activity.
Concept
We usually subtract by going backward. But what if the problem is 19 - 17 = ? Counting backward 17 times would be exhausting! Let's use the Distance Trick.
π― The Distance Trick (Counting On): When the two numbers in a subtraction problem are very close together on the number line, just count the steps between them! 1. Start at the small number: Start at 17. 2. Count UP to the big number: Say "18, 19". 3. How many steps? You took 2 steps forward! So, 19 - 17 = 2.
You just turned a scary subtraction problem into a super easy counting game!
Try it
Find the distance!
Instructions: Start at the small number and count up to the big number.
Problem 1: 16 - 14 = ? * Start at 14. Count up: "15, 16". * That's ___ steps! * Answer: ___
Problem 2: 20 - 18 = ? * Start at 18. Count up to 20. * Answer: ___
Problem 3: 15 - 12 = ? * Answer: ___
Problem 4: 18 - 17 = ? * Answer: ___