Instructions
- Complete each activity in order. Start with counting and number recognition, then try the practical problems.
- Write neatly and show your thinking when asked.
- You may use counters, coins, small toys, or drawings to help you count.
- Check your answers in the Answer Key when you finish.
Learning goals: I can recognize, write, count, compare, and use the number 20.
1. Meet the Number 20
Trace or copy the number several times.
20 20 20 20 20
Write the number 20 three times:
Complete the sentence:
There are __ ones in the number 20.
2. Count to 20
Fill in the missing numbers.
- 1, 2, 3, _____, 5
- 6, 7, _____, 9, 10
- 11, _____, 13, 14, 15
- 16, 17, _____, 19, 20
- 2, 4, 6, _____, 10
- 10, 12, 14, _____, 18, 20
3. Count the Groups
Count each group. Write the total.
- ● ● ● ● ● = ____
- ★ ★ ★ ★ ★ ★ ★ = ____
- ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ = ____
- ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ = ____
Draw enough circles to make 20:
● ● ● ● ● ● ● ● ● ● ____
How many more circles did you draw? ____
4. Tens and Ones
Remember: 20 is 2 tens and 0 ones.
Complete each statement.
- 20 = tens and ones
- 10 + 10 = _____
- 19 + 1 = _____
- 20 - 1 = _____
- 20 has _____ groups of ten.
5. Before, After, or Between
Write the missing number.
- _____, 20
- 20, _____
- 18, _____, 20
- _____, 19, 20
- 15, 16, _____, 18, 19, 20
6. Compare the Numbers
Write <, >, or =.
- 20 _____ 18
- 15 _____ 20
- 20 _____ 20
- 19 _____ 20
- 20 _____ 12
7. Make 20 in Different Ways
Complete each number bond or addition sentence.
Example: 10 + 10 = 20
- 1 + _____ = 20
- 5 + _____ = 20
- 8 + _____ = 20
- 12 + _____ = 20
- 15 + _____ = 20
- + = 20
8. A Number 20 Investigation
Record different ways to make 20. The example row is completed for you.
| First number | Second number | Addition sentence |
|---|---|---|
| 10 | 10 | 10 + 10 = 20 |
9. Real-World Math: The Party Table
A party table has 20 cups. Solve each problem.
-
The helper puts 5 cups on the table. How many cups are still in the box?
20 - 5 = ____ cups
-
The helper puts 10 more cups on the table. How many cups are on the table now?
5 + 10 = ____ cups
-
There are 20 guests. Each guest needs 1 cup. Are there enough cups? Circle one.
Yes No
-
If 3 cups are used, how many cups are left?
20 - 3 = ____ cups
10. Show 20 in Three Ways
Show the number 20 by doing all three tasks.
-
Draw 20 objects:
-
Write an addition sentence that equals 20:
____ + ____ = 20
-
Write a subtraction sentence that equals 20:
____ - ____ = 20
11. Think and Explain
Answer in words, numbers, or pictures.
-
Which is easier for you: counting to 20 or writing the number 20? Why?
-
Where might you see or use the number 20 in real life?
Optional Challenge
-
There are 20 apples. You put them equally into 2 baskets. How many apples go in each basket?
____ apples in each basket
-
Find three different addition sentences that equal 20. Do not use 10 + 10.
a. __
b. __
c. __
-
I am a number greater than 15 and less than 20. I am an even number. What number could I be?
Answer Key
1. Meet the Number 20
- The three copied numbers should each be 20.
- There are 20 ones in the number 20.
2. Count to 20
- 4
- 8
- 12
- 18
- 8
- 16
3. Count the Groups
- 5
- 7
- 10
- 12
- Students should draw 10 more circles. The completed group has 20 circles.
4. Tens and Ones
- 2 tens and 0 ones
- 20
- 20
- 19
- 2
5. Before, After, or Between
- 19
- 21
- 19
- 18
- 17
6. Compare the Numbers
- 20 > 18
- 15 < 20
- 20 = 20
- 19 < 20
- 20 > 12
7. Make 20 in Different Ways
- 19
- 15
- 12
- 8
- 5
- Answers may vary, such as 7 + 13 = 20.
8. A Number 20 Investigation
Answers may vary. Possible rows include:
- 1 + 19 = 20
- 2 + 18 = 20
- 5 + 15 = 20
- 8 + 12 = 20
- 9 + 11 = 20
9. Real-World Math
- 15 cups
- 15 cups
- Yes
- 17 cups
10. Show 20 in Three Ways
- The drawing should show 20 objects.
- Addition answers may vary, such as 7 + 13 = 20.
- Subtraction answers may vary, such as 25 - 5 = 20.
11. Think and Explain
- Answers will vary.
- Answers may include clocks, money, scores, groups of objects, or page numbers.
Optional Challenge
- 10 apples
- Answers may vary, such as 1 + 19 = 20, 5 + 15 = 20, and 8 + 12 = 20.
- 16 or 18