K-5 friendly lesson

Try one idea, then jump into the activity.These lessons are designed to feel short, friendly, and easy to follow.

Subtracting 8

🕷️ An octopus has 8 legs. If we subtract them all, how many are left? Let's use our tricks on number 8!

Lesson 2

Concept

8 is a big number to take away. The fastest way to subtract 8 is to **Count On up to the 10**! 🎯 **The "Count On from 8" Strategy:** **Example: 13 - 8 = ?** 1. 8 is super close to 10! It's only **2 steps** away. 2. The number 13 is **3 steps** past 10. 3. Just add your steps together! 2 + 3 = 5. So, **13 - 8 = 5**. Any time you subtract 8 from a teen number, the answer is just the "ones" digit plus 2! * 1**4** - 8 = 4 + 2 = **6**. * 1**7** - 8 = 7 + 2 = **9**.

Try it

Let's try the plus-two rule! **Instructions:** Subtract 8 by adding 2 to the ones digit (or use your favorite strategy). **Problem 1: 15 - 8 = ?** * Add 2 to the 5. (2 + 5 = 7) * Answer: 15 - 8 = ___ **Problem 2: 12 - 8 = ?** * Add 2 to the 2. * Answer: ___ **Problem 3: 16 - 8 = ?** * (Wait! Is this a double?) * Answer: ___ **Problem 4: 11 - 8 = ?** * Answer: ___