Chapter 7 · Consolidation and enhancement

Lesson 7.6 · Mathematics plaza — matching

Hua's Classroom for Shanghai Maths — One Lesson One Exercise (English edition, pages 142–144).

Grade 3 Second Semester Pages 142–144 ECNU Press

Lesson Alignment

How this Shanghai Maths lesson connects to learning goals, Common Core, and Eureka Math.

Learning Objectives

Students will be able to:

  1. 01Count boy–girl host pairs. (Question 1)
  2. 02Count games if every two play once. (Question 2)
  3. 03Order river-crossing steps. (Question 3)

Common Core Standards

CodeStandard (focus for this lesson)
3.OA.D.8Multi-step reasoning.
MP.7Look for structure.

Eureka Math Correspondence

Shanghai MathsFocusEureka Math
CombinationsPairsG3 plaza
OrderSequenceG3 plaza

Core Concepts

Count pairings, games, and river-crossing step orders.

Pair Selections

Choose 1 boy from B and 1 girl from G → $B \times G$ ways.

Tournament Games

Every two of 5 play once → $5\times4\div2 = 10$ games.

Arrange the Order

River crossing: dog, rabbit, grass — sequence steps so nothing is eaten.

Key Terms & Definitions (Reference)

Quick glossary for this lesson.

TermDefinition
CombinationA selection without regard to order.
PermutationAn ordered sequence of steps.

Key Answers

Quick reference for this lesson’s exercise answers.

Key answers

  1. $3\times2=6$ selections.
  2. $3\times3\times2=18$ outfits.
  3. $4\times5=20$ two-digit numbers.
  4. $C(5,2)=10$ games.
  5. (1) 3 routes; (2) route ② (1000 m).
  6. MCQ: C (7 lengths); C (7 masses).
  7. Order: A → D → B → C.
  8. Tickets 72; fares 36.
  9. 16 ways (compositions of 5).
  10. 72 ways on $4\times4$ grid.