Curriculum  /  Math  /  2nd Grade  /  Unit 2: Adding and Subtracting Within 100  /  Lesson 2

Adding and Subtracting Within 100

Lesson 2

Math

Unit 2

2nd Grade

Lesson 2 of 21

Objective

Add and subtract multiples of ten to two-digit numbers.

Student-Facing

I can add and subtract multiples of ten to two-digit numbers.

Common Core Standards

Core Standards

  • 2.NBT.B.5 — Fluently add and subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction.

Foundational Standards

  • 1.NBT.C.4
  • 1.NBT.C.5
  • 1.NBT.C.6

Criteria for Success

  1. Recognize and understand patterns of adding and subtracting multiples of ten to two-digit numbers.
  2. Solve problems within 100.

Tips for Teachers

This lesson provides students with an opportunity to re-engage in first grade standard 1.NBT. 6 with adding and subtracting multiples of ten to two-digit numbers. Students have the opportunity to see adding and subtracting multiples of ten concretely with base ten blocks, pictorially with drawings, and then more abstractly. This progression can provide support to those who need it and push everyone along in more abstract thinking.

Lesson Materials

  • Optional: Hundreds Chart (1 per student)
  • Base ten blocks (teacher set: 10 tens and 10 ones) — optionally, you may want to provide a set to any student who may benefit from them

Warm Up

5-10 minutes

Unlock warm-up activities that help you engage every student and prepare them for the day’s lesson with a Fishtank Plus subscription.

Anchor Tasks

15-25 minutes

Problem 1

Mrs. Jackson is counting her base ten blocks before math time. She has a tray with some tens and ones and another tray with just tens. 

a.   What is the value of base ten blocks in both trays?

b.   Write an equation to show how you found the total value of the base ten blocks in the two trays.

Purpose

Create a free account or sign in to access the Purpose for this Anchor Problem.

Set Up

Create a free account or sign in to access the Set Up for this Anchor Problem.

Upgrade to Fishtank Plus to view Facilitation Guidance and Sample Student Response for this Anchor Task.

Problem 2

Complete the drawing to solve the equation.

a.   58 - 20 = _____

b.   36 + 40 = _____

c.   20 + 42 = _____

Purpose

Create a free account or sign in to access the Purpose for this Anchor Problem.

Upgrade to Fishtank Plus to view Facilitation Guidance and Sample Student Response for this Anchor Task.

Problem 3

Complete each equation with the number that makes it true. 

a.   21 = 51 - _____

b.   74 = 40 + _____

c.   20 +_____= 68

d.   83 - _____= 23

Purpose

Create a free account or sign in to access the Purpose for this Anchor Problem.

Upgrade to Fishtank Plus to view Facilitation Guidance and Sample Student Response for this Anchor Task.

Problem Set

15-20 minutes

Target Task

5-10 minutes

Fill in the blanks with the missing numbers.

a.   48 + 20 = _____

b.   64 + _____ = 94

c.   57 - 30 = _____

d.   38 = 78 - _____

Student Response

Additional Practice

Daily Word Problems, Warm Ups, and Center Activities are aligned to the content of the unit but not necessarily to the lesson objective, therefore feel free to use them anytime during your school day.

Word Problems and Fluency Activities

Next

Use make a ten strategies to add two-digit numbers within 50.

Lesson 3
icon/arrow/right/large

Lesson Map

A7CB09C2-D12F-4F55-80DB-37298FF0A765

Topic A: Adding & Subtracting with Multiples of Ten

Topic B: Strategies for Adding within 100

Topic C: Strategies for Subtracting within 100

Topic D: Working within 100 and Categorical Data

Request a Demo

See all of the features of Fishtank in action and begin the conversation about adoption.

Learn more about Fishtank Learning School Adoption.

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Yes

No

Any other information you would like to provide about your school?

We Handle Materials So You Can Focus on Students

We Handle Materials So You Can Focus on Students

We've got you covered with rigorous, relevant, and adaptable math lesson plans for free