Subtract 3-Digit Models (No Regrouping)
āļø The Giant Demolition! We have to cross out Flats, Rods, and Cubes to find out what is left standing in the city.
Concept
Drawing the blocks is the perfect way to double check your test answers if you get confused. šÆ **The Triple Cross-Out Rule:** **Example: 356 - 124 = ?** 1. **Draw the start (356):** 3 Flats, 5 Rods, 6 Cubes. 2. **Attack the Cubes! (-4):** Cross out 4 of the Cubes. (Leaves 2). 3. **Attack the Rods! (-2):** Cross out 2 Long Rods. (Leaves 3). 4. **Attack the Flats! (-1):** Cross out 1 Giant Flat. (Leaves 2). 5. **Count the survivors:** 2 Flats, 3 Rods, 2 Cubes. 6. **Answer:** **232**!
Try it
Demolish the towers! **Instructions:** Imagine the starting blocks. Cross out the exact number the bad guy tells you to cross out. **Problem 1: 458 - 213 = ?** * Cubes: 8 - 3 = ___ cubes safe. * Rods: 5 - 1 = ___ rods safe. * Flats: 4 - 2 = ___ flats safe. * Answer: ___ **Problem 2: 689 - 345 = ?** * Answer: ___ **Problem 3:** You see a picture: 5 Flats, 4 Rods, 2 Cubes. The paper tells you to cross out 2 Flats, 1 Rod, and 0 Cubes (- 210). * Answer: ___ **Problem 4:** Subtract 102 from 834. * Answer: ___