Grade 2 Math

Weeks: 3/23-3/27 Day 4

Standard: 2NBT5 - I can subtract within 100 using strategies based on place value, properties of operations, and/or the relationship between addition and subtraction. Objective: students will learn to subtract by counting backwards on an open number line Instructional learning videos to support the objective: https://www.youtube.com/watch?v=0ABI7UFDg2o https://www.youtube.com/watch?v=uq8yIaCl-G4

Practice Worksheet: EnVisions Topic 5, Lesson 5-3 (copy pages) Problem Of the Day: Choose a Number between 50 and 150

Games to play to support addition and/or subtraction:

Digital: https://www.abcya.com/games/ducky_race_subtraction

Other (number cards can be used, 0-9, or just made on paper or can use dice):

Add 10 on a Number Line game (copy)

Additional Online Resources:

• STMath.org • Imagine Math (via Clever) Learn Glossary

Find 68 - 23. One Way Another Way 23 is 2 tens and 3 ones. You can subtract 68 - 20 = 48, Let's use an So, count back 2 tens from 68. then 48 - 3 = 45. open number line and 58, 48 - 3 - 20 count back. First, place Then, count back 3 ones from 48. 68 on the line. 47, 46, 45 - 1- 1- 1 - 10 - 10 4845 68 So, 68 - 23 = 45 . I can check my 68 45 46 4847 58 68 subtraction by adding 45 23 68.

Do You Understand? Use an open number line to find each difference. Show Me! How can the open number line help you keep track as you count 1. 28 - 24 = - 4 - 10 - 10 back?

84 18 28

2. 50 - 35 =

268 two hundred sixty-eight © Pearson Education, Inc. 2 Topic 5 Lesson 3 Name Tools Assessment

Use an open number line to find each difference.

3. 45 - 13 = 4. 63 - 22 =

5. 78 - 46 = 6. 92 - 37 =

7. 80 - 44 = ? 8. Number Sense How many tens and ones Break apart the will you count back to solve this problem: number you are subtracting 56 38 ? Solve the problem. into tens and ones. - =

tens ones

- = - = Topic 5 Lesson 3 two hundred sixty-nine 269 Use an open number line to solve each problem.

9. MP.5 Use Tools There are 47 raffle 10. MP.5 Use Tools Ethan counts 78 carrots. tickets to sell for the fair. Ms. Brown’s class He sells 35 carrots at the farmers market. sells 23 raffle tickets. How many raffle How many carrots does Ethan have left? tickets are left to sell?

raffle tickets carrots

11. Higher Order Thinking Show two 12. Assessment Jen solved a subtraction different ways to find 63 - 25 using the problem using the open number line open number lines. shown. Write the equation that her work below shows.

- 2 - 10 - 10

3634 46 56

- =

63 - 25 =