# Add or Subtract 10 or 100

2nd Grade • Half Day Lesson Plan## Quick Facts

Subject: Math, Numbers and Operations in Base Ten

Type: Half Day Lesson Plan

CCSS: 2.NBT.1, 2.NBT.8

Skills: Mental math, add 10 or 100 to a number, subtract 10 or 100 from a number, Place value, three digits in a three-digit number represents ones, tens, hundreds

File Type: PDF Document

Materials Needed: pencils, small sticky notes or counting chips to cover up numbers on number grid, student whiteboards, dry erase markers, erasers (1 per student), deck of cards (number cards only-remove face cards) (1 per small group of students), brads and paperclips to make spinners, and a document camera or whiteboard

Printable Resources:
**Required Printable Resources:** “Number Grid 101-200” (1 copy per student) (1 for display), “Mental Math” (1 copy per student) (1 for display), “Spin, Add or Subtract” (1 copy per pair of student), “What’s My Number?” (1 copy per pair of students), “Flip and Solve” (1 copy per pair of students)
**Optional Printable Student Resources:** “Exit Slips” (as an optional assessment component) (1 copy per student)

## Lesson Plan Description

This half day lesson plan is broken down into 2 separate segments (30-60 minutes each) addressing Numbers in Base-Ten: Adding and Subtracting 10 and 100 (2.NBT.1 & 2.NBT.8). These lessons include: guided and independent practice of concepts, and 3 games to reinforce the concept of adding and subtracting 10 and 100.

**Segment 1:**students will find patterns on a number grid and discuss how place value can help find 10 and 100 more or 10 or 100 less than a number without counting, explain their reasoning on how they find 10 or 100 more or 10 or 100 less than a number, and solve equations adding 10 or 100 and subtracting 10 or 100 using mental math.**Segment 2:**students will play the games: “Spin, Add, or Subtract,” “What’s My Number?,” and “Flip and Solve” to practice solving equations adding 10 or 100 and subtracting 10 or 100 using mental math.

These lessons can be taught over the span of a half day or you can use the lessons independently, broken up over several days.