Chapter 2 · Multiplying and dividing by two-digit numbers

Lesson 2.9 · Dividing two-digit or three-digit numbers by a two-digit number (1)

Hua's Classroom for Shanghai Maths — One Lesson One Exercise (English edition, pages 46–48).

Grade 3 Second Semester Pages 46–48 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. 01Divide 2- and 3-digit by 2-digit using column method. (Question 1)
  2. 02Interpret remainders in context. (Question 2)
  3. 03Compare speeds m/s to rank race results. (Question 3)

Common Core Standards

CodeStandard (focus for this lesson)
4.NBT.B.6Divide up to four digits by one digit; extend.
3.OA.A.3Interpret quotients.

Eureka Math Correspondence

Shanghai MathsFocusEureka Math
Column ÷Two-digit divisorG4 M3
Speed rankm/s compareG3 M7

Core Concepts

Introduce two-digit ÷ two-digit column; animal-race speed ranking.

Two-Digit Divisor

Estimate quotient digit; multiply divisor × trial quotient; adjust if too large.

Remainders

Remainder must be less than divisor; interpret in word problems.

Speed Ranking

Compare metres/second — larger speed wins the race.

Key Terms & Definitions (Reference)

Quick glossary for this lesson.

TermDefinition
QuotientResult of division.
Trial quotientFirst guess at how many times divisor fits.

Key Answers

Quick reference for this lesson’s exercise answers.

1. Mental

  • $6\div2=3$,\; $60\div2=30$,\; $60\div20=3$; similarly $8/80/40$,\; $9/90/30$,\; $21/210/70$

2. Think carefully

  1. $99\div23=4\cdots7$
  2. $517\div63=8\cdots13$

3. Column method

  • $174\div21=8\cdots6$;\; $195\div53=3\cdots36$;\; $132\div22=6$
  • $347\div43=8\cdots3$;\; $608\div86=7\cdots6$

4. Application

  1. 1st goat, 2nd cat, 3rd elephant (same distance $\Rightarrow$ compare speeds)
  2. Daily averages $9$,\; $12$,\; $14$

5. Enhancement — hire vehicles

  1. $4$ coaches, $1920$ yuan
  2. $11$ minibuses, $2200$ yuan
  3. Prefer coaches (cheaper); mix $3$ coaches $+2$ minibuses $=1840$ yuan also possible