Curriculum  /  Math  /  2nd Grade  /  Unit 2: Adding and Subtracting Within 100  /  Lesson 1

Adding and Subtracting Within 100

Lesson 1

Math

Unit 2

2nd Grade

Lesson 1 of 21

Objective

Add and subtract 1 and 10 to or from two-digit numbers within 100.

Student-Facing

I can add and subtract 1 and 10 to or from 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 patterns for adding and subtracting 1 and 10 within 100 for two-digit numbers.
  2. Relate numerical equations and sentences to adding and subtracting within 100.

Tips for Teachers

  • In Unit 1, students extended their count sequence from 120 and here they focus more intentionally on working with numbers within 100. A hundreds chart can be a helpful visual for students as they build their fluency with adding and subtracting numbers within 100. Having adept knowledge of numbers 1 through 100 allows students to think flexibly about number relationships as they add and subtract. 
  • Throughout the unit you will see reference to "friendly" numbers. We use this term to indicate numbers that are easy to work with and may often end in a zero, also referred to as benchmark numbers. Feel free to refer to these numbers as friendly numbers, benchmark numbers, or landmark numbers, whichever makes sense for you and your students. 

Lesson Materials

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

Find the numbers that make each statement true.

a.   53 is 10 more than _____.

b.   1 more than 69 is _____.

c.   _____ is 10 less 67.

d.   1 less than 61 is _____.

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 2

Sara Sonia uses an arrow, like shown below, to show the relationship between two numbers.

Use Sara Sonia's example as a model to show the relationship between the numbers below.

a.   100 to 90

b.   73 to 74

c.   68 to 78

d.   99 to 98

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

Find the pattern and then complete the sequence.

a.   43, 53, 63, _____, _____, _____

b.   76, 77, 78, _____, _____, _____

c.   58, 57, 56, _____, _____, _____

d.   67, 57, 47, _____, _____, _____

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 4

Fill in the blank to make each equation true.

a.   70 = 69 + _____

b.   80 = 90 - _____

c.   _____ + 1 = 48

d.   55 + 10 = _____

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

Problem 1

Complete each statement to make it true.

a.   72 is 10 more than _____.

b.   84 is _____ less than 94.

Student Response

Problem 2

Fill in the blank to make each equation true.

a.   _____ + 1 = 37

b.   44 =  _____ - 10

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

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

Lesson 2
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