Addition and Subtraction Basic Facts Lesson:

Bar diagrams and math mountains for addition and subtraction: relating everything to PPW

Practice problems:

1. What are some advantages of using part-whole language and diagrams when solving addition and subtraction problems?

It helps children:

• connect addition and subtraction problems of all types
• understand that subtraction problems can be thought of as missing number addition problems,
• organize their knowledge in a way that knowledge about adding can be used to figure out subtraction problems.

2. What's the other name for a part-whole diagram?

bar diagram

3. What's the other name for a number bond diagram?

math mountain

4. In a math mountain, what number goes on the top of the mountain? What numbers go on the bottom of the mountain?

The whole goes on top, and the parts go on the bottom.

5. What manipulative work does a part-whole diagram resemble?

Counters that are snapped together to make a bar, or Cuisenaire rods.

6. How can you represent the unknown quantity in a part-whole or number bond diagram?

With a question mark, or an empty square, circle, or line to show where the answer will go.

7. If you write a the number sentence: 11-4=? to show how to solve a problem, what other number sentence could you write that would do the same thing?

You could (and should) also write 4+?=11

8. In a Join problem, what is the whole? What are the parts?

The whole is the result, and the parts are the start and change amounts.

9. In a Separate problem, what is the whole? What are the parts?

The whole is the start amount, and the parts are the change and result amounts.

10. In a Compare problem, what is the whole? What are the parts?

The whole is the larger compared set, and the parts are the smaller compared set and the difference.

11. For each of the following word problems:

• draw a Part-Whole diagram. Label the diagram with words as well as numbers.
• draw a math mountain
• write the appropriate number sentence or sentences.

a. Lisa had some fairies. For her birthday, she got 3 more fairies. Now she has 11 fairies. How many fairies did she have before her birthday?

b. Ellen had 14 erasers . She gave 8 erasers to Kallie. How many erasers does Ellen have left?

c. Jane had some crackers. She ate 2 crackers. Now she has 3 crackers left. How many crackers did she have before she ate any of them?

d. Kendra has 8 sharp pencils and 3 dull pencils. How many more sharp pencils than dull pencils does Kendra have?

e. Callie has 14 butterfly stickers. She has 8 more butterfly stickers than Shauna. How many butterfly stickers does Shauna have?