A fundamental topic in math!
Two-Digit Mixed Addition and Subtraction with Regrouping
When adding or subtracting two-digit numbers, we may need to regroup or borrow from tens to hundreds, or vice versa. Here are some examples:
Addition with Regrouping:
1. 14 + 25 = ?
Step 1: Add ones digits (4 + 5 = 9)
Step 2: Add tens digits (10 + 20 = 30)
* Carry 1 from the ones place to the tens place
Step 3: Combine the answers (30 + 1 = 31)
Final answer: 31
2. 46 + 93 = ?
Step 1: Add ones digits (6 + 3 = 9)
Step 2: Add tens digits (40 + 90 = 130)
* Carry 1 from the tens place to the hundreds place
Step 3: Combine the answers (130 + 1 = 131)
Final answer: 131
Subtraction with Regrouping:
1. 75 – 32 = ?
Step 1: Subtract the ones digits (5 – 2 = 3)
Step 2: Subtract the tens digits (70 – 30 = 40)
* Borrow 1 from the tens place to the hundreds place
Step 3: Combine the answers (40 – 1 = 39)
Step 4: Combine the answers from steps 1 and 3 (39 + 3 = 42)
Final answer: 42
2. 95 – 67 = ?
Step 1: Subtract the ones digits (5 – 7 = -2)
Step 2: Subtract the tens digits (90 – 60 = 30)
* Borrow 1 from the hundreds place to the tens place
Step 3: Combine the answers (30 – 1 = 29)
Step 4: Combine the answers from steps 1 and 3 (29 – 2 = 27)
Final answer: 27
Two-Digit Mixed Addition and Subtraction without Regrouping
When adding or subtracting two-digit numbers without regrouping, we simply add or subtract the digits as usual:
Addition without Regrouping:
1. 14 + 17 = ?
Step 1: Add ones digits (4 + 7 = 11)
Step 2: Add tens digits (10 + 10 = 20)
Final answer: 20
2. 46 + 23 = ?
Step 1: Add ones digits (6 + 3 = 9)
Step 2: Add tens digits (40 + 20 = 60)
Final answer: 60
Subtraction without Regrouping:
1. 78 – 24 = ?
Step 1: Subtract the ones digits (8 – 4 = 4)
Step 2: Subtract the tens digits (70 – 20 = 50)
Final answer: 54
2. 93 – 17 = ?
Step 1: Subtract the ones digits (3 – 7 = -4)
Step 2: Subtract the tens digits (90 – 10 = 80)
Final answer: 76
Remember to always check your calculations and adjust as needed!
