Instructions
- Complete the activities in order, starting with counting and place value.
- Write numbers neatly and show your thinking when solving problems.
- Use counters, coins, or small objects if you need help.
- Try the optional challenge after completing all 20 questions.
1. Counting to 20
A. Fill in the missing numbers.
- 1, 2, 3, , 5, 6, , 8, 9, 10
- 11, , 13, 14, , 16, 17, ___, 19, 20
- , 2, 4, 6, , 10, 12, ___, 16, 18, 20
- 20, 19, , 17, 16, , 14, 13, ___, 11
B. Write the number that comes before and after.
| Number | Before | After |
|---|---|---|
| 7 | 6 | 8 |
| 12 | ||
| 18 | ||
| 5 | ||
| 15 | ||
| 19 |
2. Understanding 20
- Circle the group that shows 20 objects.
- ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
- ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
- ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● ●
-
Draw 20 stars in the space below.
-
Write the number word for 20: __
-
Write the numeral for twenty: __
-
Complete the place-value statement:
20 has ten and ones.
- Which number is greater? Circle one.
18 or 20
3. Making 20
Example: 10 + 10 = 20
- Complete each number bond or equation.
| First Part | Second Part | Total |
|---|---|---|
| 10 | 10 | 20 |
| 5 | 20 | |
| 8 | 20 | |
| 12 | 20 | |
| 15 | 20 | |
| 1 | 20 |
- Write two different addition equations that equal 20.
a. __
b. __
- Complete the pattern:
2 + 18 = 20 4 + 16 = 20 6 + = 20 8 + = 20
- You have 13 red blocks. How many blue blocks do you need to have 20 blocks altogether?
Equation: __
Answer: You need __ blue blocks.
4. Adding and Taking Away
- Solve.
- 10 + 5 = __
- 7 + 8 = __
- 12 + 6 = __
- 9 + 9 = __
- Solve.
- 20 − 5 = __
- 20 − 8 = __
- 17 − 7 = __
- 19 − 9 = __
- A shelf has 20 books. A child takes 6 books to read. How many books remain on the shelf?
Equation: __
Answer: __ books remain.
- A bakery makes 14 muffins in the morning and 6 muffins in the afternoon. How many muffins does it make altogether?
Equation: __
Answer: The bakery makes __ muffins.
5. Real-World Math Mission
- Plan a collection of 20 objects. Choose one type of object, such as buttons, blocks, coins, or stickers. Draw or list your collection.
My objects are: ____
How many groups can you make? __
How many objects are in each group? _____
- Explain one way you might use the number 20 in everyday life.
Optional Challenge
A toy store has 20 toy cars. It sells 7 cars in the morning and buys 5 more cars in the afternoon. How many toy cars does the store have now?
Show your steps:
Answer: __ toy cars
Answer Key
- 4, 7
- 12, 15, 18
- 0, 8, 14
- 18, 15, 12
- The first group shows 20 objects.
- Answers will vary; there should be 20 stars.
- twenty
- 20
- 2 tens and 0 ones
- 20
- 15, 5, 12, 8, 15, 5, 19, 1
- Answers will vary. Examples: 11 + 9 = 20; 14 + 6 = 20.
- 14, 12
- 13 + 7 = 20; 7 blue blocks
- 15, 15, 18, 18
- 15, 12, 10, 10
- 20 − 6 = 14; 14 books
- 14 + 6 = 20; 20 muffins
- Answers will vary, but the total should be 20 objects.
- Answers will vary. Examples include 20 minutes, 20 cents, or 20 steps.
Optional Challenge: 20 − 7 + 5 = 18; 18 toy cars