Grade: 4 Subject: Math Unit: Multi-Digit Multiplication Lesson: 3 of 6 SAT: Algebra ACT: Math

Guided Practice

Learn

In this lesson, we will work through multi-digit multiplication problems together, step by step. Guided practice helps you build confidence before working independently.

The Standard Algorithm Review

When multiplying multi-digit numbers, we use the standard algorithm:

  1. Write the numbers vertically, aligning the ones place
  2. Multiply each digit of the bottom number by each digit of the top number
  3. Remember to add placeholder zeros for each new row
  4. Add all partial products together

Key Tips for Success

  • Always start from the ones place
  • Write neatly and keep columns aligned
  • Double-check your carrying
  • Estimate first to check if your answer is reasonable

Examples

Example 1: 34 x 12

Step 1: Multiply 34 by 2 (ones digit of 12)

34 x 2 = 68

Step 2: Multiply 34 by 10 (tens digit of 12)

34 x 10 = 340

Step 3: Add the partial products

68 + 340 = 408

Example 2: 156 x 23

Step 1: Multiply 156 by 3

156 x 3 = 468

Step 2: Multiply 156 by 20

156 x 20 = 3,120

Step 3: Add the partial products

468 + 3,120 = 3,588

Practice

Work through these problems step by step. Click on each question to reveal the answer and solution.

Question 1: What is 25 x 14?

Answer: 350

Solution: 25 x 4 = 100, and 25 x 10 = 250. Then 100 + 250 = 350.

Question 2: What is 43 x 21?

Answer: 903

Solution: 43 x 1 = 43, and 43 x 20 = 860. Then 43 + 860 = 903.

Question 3: What is 67 x 15?

Answer: 1,005

Solution: 67 x 5 = 335, and 67 x 10 = 670. Then 335 + 670 = 1,005.

Question 4: What is 128 x 13?

Answer: 1,664

Solution: 128 x 3 = 384, and 128 x 10 = 1,280. Then 384 + 1,280 = 1,664.

Question 5: What is 245 x 12?

Answer: 2,940

Solution: 245 x 2 = 490, and 245 x 10 = 2,450. Then 490 + 2,450 = 2,940.

Question 6: What is 89 x 27?

Answer: 2,403

Solution: 89 x 7 = 623, and 89 x 20 = 1,780. Then 623 + 1,780 = 2,403.

Question 7: What is 156 x 34?

Answer: 5,304

Solution: 156 x 4 = 624, and 156 x 30 = 4,680. Then 624 + 4,680 = 5,304.

Question 8: What is 312 x 25?

Answer: 7,800

Solution: 312 x 5 = 1,560, and 312 x 20 = 6,240. Then 1,560 + 6,240 = 7,800.

Question 9: What is 478 x 16?

Answer: 7,648

Solution: 478 x 6 = 2,868, and 478 x 10 = 4,780. Then 2,868 + 4,780 = 7,648.

Question 10: What is 625 x 24?

Answer: 15,000

Solution: 625 x 4 = 2,500, and 625 x 20 = 12,500. Then 2,500 + 12,500 = 15,000.

Check Your Understanding

Before moving on, make sure you can:

  • Set up a multi-digit multiplication problem vertically
  • Break down multiplication into partial products
  • Add partial products correctly
  • Estimate to check if your answer is reasonable

Next Steps

  • Review any concepts that felt challenging
  • Move on to the next lesson when ready
  • Return to practice problems periodically for review