1. **State the problem:** Multiply a 4-digit number by a 2-digit number with regrouping. Example: Multiply 2345 by 67. 2. **Write the numbers vertically:** 2345 x 67 3. **Multiply the ones digit of the bottom number (7) by each digit of the top number starting from the right:** 7 \times 5 = 35, write 5 and carry 3. 7 \times 4 = 28, plus 3 carried = 31, write 1 and carry 3. 7 \times 3 = 21, plus 3 carried = 24, write 4 and carry 2. 7 \times 2 = 14, plus 2 carried = 16, write 16. So, first partial product is 16415. 4. **Multiply the tens digit of the bottom number (6) by each digit of the top number, remember to add a zero at the end (since it's tens place):** 6 \times 5 = 30, write 0 and carry 3. 6 \times 4 = 24, plus 3 carried = 27, write 7 and carry 2. 6 \times 3 = 18, plus 2 carried = 20, write 0 and carry 2. 6 \times 2 = 12, plus 2 carried = 14, write 14. So, second partial product is 140700. 5. **Add the two partial products:** 16415 +140700 =157115 6. **Final answer:** $$2345 \times 67 = 157115$$ This method uses regrouping (carrying) at each step to handle products greater than 9.