Mixed Practice: Subtracting Groups of 10 or 100
šµļøāāļø The Dial Breaker! Check the zeros to see if you are destroying the Hundreds digit, or the Tens digit!
Concept
Okay, same trick as the Addition chapter. You MUST check the number of zeros before you do the math! šÆ **The "Check the Attack" Strategy:** * **ONE Zero (Example: - 40):** Only attack the TENS! The Hundreds and Ones are safe! * 8**6**2 - **2**0 = 8**4**2. (6-2). * **TWO Zeros (Example: - 400):** Only attack the HUNDREDS! * **8**62 - **2**00 = **6**62. (8-2).
Try it
Check the zeros! Which dial is under attack? **Instructions:** Figure out if you are subtracting the Tens digit or the Hundreds digit! **Round 1: Tens Attack! (One Zero)** 1. 5**8**1 - **3**0 = ___ (500 is safe!) 2. 2**4**9 - **1**0 = ___ **Round 2: Hundreds Attack! (Two Zeros)** 3. **9**32 - **4**00 = ___ (The 32 is safe!) 4. **4**85 - **3**00 = ___ **Round 3: The Blender! (Mixed Up)** 5. 650 - 200 = ___ 6. 471 - 50 = ___ 7. 888 - 400 = ___ 8. 392 - 60 = ___