Multi-Digit Multiplication
Multiplication is how we add quickly. When numbers get big — like 347 × 28 — we use the standard algorithm: multiply by each digit and add up the partial products. Mastering this opens the door to area, volume, and real-world problems.
Key Concepts
Place Value in Multiplication
When you multiply 347 × 28, you first do 347 × 8 (ones place), then 347 × 20 (tens place, so add a zero). Each result is a partial product. Add them together to get your answer. Every digit has a value based on its position.
Estimation First
Before solving, estimate: 347 × 28 ≈ 350 × 30 = 10,500. If your answer is way off from your estimate, you made an error somewhere. Estimation is a habit every strong math student builds.
Multi-Step Word Problems
Real problems combine operations: 'A school orders 24 boxes of crayons with 48 crayons each, and 36 boxes with 64 crayons each. How many total?' Break it into steps: 24×48, then 36×64, then add. One step at a time.
🆕 Multiplication Machine
Enter two numbers and see the step-by-step partial products method!
✅ Check Your Understanding
1. What is a partial product?
2. Why should you estimate before solving?
3. What is 300 × 40?