Subtract a 1-Digit from a 2-Digit (With Regrouping)
šØ The ultimate subtraction trick! Borrowing! It's time to perform the "Smash a Ten" trick using only vertical numbers.
Concept
This is the famous "Borrowing" trick that every math genius uses! šÆ **The Borrowing Code:** **Example: 42 - 6 = ?** 4 2 - 6 -------- 1. **"More on Top? No need to stop! More on the Floor? Go next door!"** The 6 is on the floor, and it's bigger than 2! We can't do 2 - 6. Go next door! 2. **Borrow from the neighbor:** Look at the 4 (in the Tens place). Cross it out! Make it a **3**. It lent you a Ten! 3. **Give to the Ones:** Give that 10 to the 2. Cross out the 2 and write an invisible little 1 in front of it to make it a **12**. 4. **Subtract the Ones:** Now we can do it! 12 - 6 = 6. 5. **Bring down the Tens:** The neighbor is a 3 now. 3 - 0 = 3. 6. **Answer:** **36**!
Try it
Go next door and borrow! **Instructions:** Use the rhyme: "More on top? No need to stop! More on the floor? Go next door!" **Problem 1:** 5 1 - 4 -------- * More on the floor? YES! 4 is bigger than 1. * Borrow from 5. (Make it a 4). Give to 1. (Make it an 11). * Ones: 11 - 4 = ___ * Answer: ___ **Problem 2:** 7 5 - 8 -------- * Answer: ___ **Problem 3:** 3 0 - 3 -------- * Answer: ___ **Problem 4:** 2 8 - 5 -------- * (Wait! More on top? No need to stop! Don't borrow on this one!) * Answer: ___