Chapter 2 · Multiplying by a one-digit number
Lesson 2.8 · Multiplying a three-digit number by a one-digit number (2)
Hua's Classroom for Shanghai Maths — One Lesson One Exercise (English edition, pages 32–34).
Lesson Alignment
How this Shanghai Maths lesson connects to learning goals, Common Core, and Eureka Math.
Learning Objectives
Students will be able to:
- 01Extend mental patterns for hundreds × one-digit. (Question 1)
- 02Reason about zeros and place-value structure of products. (Question 2)
- 03Find greatest digits under inequality constraints.
- 04Solve multi-step application and MCQ items.
Common Core Standards
| Code | Standard (focus for this lesson) |
|---|---|
| 3.NBT.A.3 | Multiples of 10 strategies. |
| 3.OA.D.8 | Multi-step problems. |
| 4.OA.A.3 | *(preview)* Multi-step with estimation. |
Eureka Math Correspondence
| Shanghai Maths | Focus | Eureka Math |
|---|---|---|
| Place value | Zeros in products | G3 M3 |
| Applications | Stock / sales stories | G3 M3 |
Core Concepts
Deepen three-digit × one-digit — mental chains, zeros, inequalities, and stories.
Mental Links
Connect $5 \times 5$, $50 \times 5$, $500 \times 5$ and similar ladders for $2 \times 5$, $3 \times 7$, $9 \times 4$.
Counting Zeros
- How many zeros at the end of $4 \times 5 \times 5$? Of $125 \times 8 \times 10$?
- How many tens in $250 \times 4$?
Inequalities & Bounds
Find the greatest digit so an inequality stays true, e.g. $\square 28 \times 4 < 1000$.
Applications
Promotion / stock stories; multi-step “sold” problems from the lesson pages.
Key Terms & Definitions (Reference)
Quick glossary for this lesson.
| Term | Definition |
|---|---|
| Trailing zeros | Zeros at the end of a product. |
| Inequality | Statement using < or >. |
| Greatest possible | Largest digit/value that still works. |
Key Answers
Quick reference for this lesson’s exercise answers.
Key answers
- Mental: $25,250,2500$; $10,100,1000$; $21,210,2100$; $36,360,3600$
- $360×4=1440$ (also $36$ tens $×4=144$ tens)
- Column: $130×6=780$; $450×9=4050$; $2×370=740$; $8×250=2000$; $5×680=3400$; $510×7=3570$. Product may be $3$- or $4$-digit.
- Fill brackets: (1) $2$; $4$ (2) $100$ tens; $125$ eights (3) $2$
- Applications: (1) $1025$ (2) $3400$ cm
- Promotion: $1360$ sets
- Multiple choice: B ($100×★=Δ$)
- Table: $1200$; $2400$; $2400$; $1200$. When one factor doubles, the product doubles (and related factor–product relationships).