Math Worksheet for 20-Year-Old Students

Instructions

1. Count carefully and write each answer in the space provided.
2. Complete the activities in order. The questions begin easily and become more challenging.
3. Use drawings, counters, or a number line to help you.
4. Check your work when you reach the Answer Key.

1. Number 20

A. Complete the number sequence.

1. 16, 17, ____, 19, 20
2. 10, 12, 14, ____, 18, 20
3. 20, 19, ____, 17, 16
4. 5, 10, 15, ____, 25

B. Write the missing numbers.

• 20 is ____ more than 19.
• 20 is ____ less than 21.
• The number before 20 is ____.
• The number after 20 is ____.

2. Count and Show 20

Draw dots, circles, or another symbol to show 20.

Try a quick way: Draw 2 groups of 10 instead of 20 separate symbols.

3. Tens and Ones

Remember: 20 has 2 tens and 0 ones.

Complete the table.

4. Compare Numbers

Write <, >, or = in each box.

1. 20 __ 18
2. 15 __ 20
3. 20 __ 20
4. 19 __ 20
5. 20 __ 12
6. 17 __ 20

Hint: The open side of the comparison symbol faces the greater number.

5. Addition to 20

Solve each problem. You may use counters or draw a number line.

1. 10 + 5 = ____
2. 12 + 3 = ____
3. 14 + 6 = ____
4. 9 + 9 = ____
5. 11 + 8 = ____
6. 15 + 5 = ____

Make 20: Write the number that completes each equation.

7. 10 + ____ = 20
8. 13 + ____ = 20
9. 16 + ____ = 20
10. 7 + ____ = 20

6. Subtraction from 20

Solve each problem.

1. 20 - 1 = ____
2. 20 - 5 = ____
3. 18 - 8 = ____
4. 17 - 7 = ____
5. 20 - 12 = ____
6. 19 - 9 = ____

7. Real-World Math

Read each situation. Write an equation and solve it.

1. A basket has 12 apples. Someone adds 8 more apples. How many apples are in the basket now?

Equation: __

Answer: __ apples

2. Maya has 20 stickers. She gives 6 stickers to a friend. How many stickers does Maya have left?

Equation: __

Answer: __ stickers

3. A bus has 15 passengers. Five more passengers get on. How many passengers are on the bus now?

Equation: __

Answer: __ passengers

8. Sort the Numbers

Write the numbers from least to greatest.

1. 20, 14, 18, 11, 16

2. 7, 19, 3, 20, 12

Write the numbers from greatest to least.

3. 13, 20, 8, 17, 15

9. Show Your Thinking

Choose one problem from this worksheet. Explain or draw how you solved it.

Problem number: __

My work:

Optional Challenge

1. Find two different addition equations that equal 20.

2. Find two different subtraction equations that equal 20.

3. I have two numbers. Their sum is 20, and one number is 4 more than the other. What are the numbers?

Answer: __ and __

Answer Key

1. Number 20

A.

1. 18
2. 16
3. 18
4. 20

B.

• 1
• 1
• 19
• 21

2. Count and Show 20

• Answers should show 20 symbols. An arrangement of 2 groups of 10 is acceptable.

3. Tens and Ones

• Example: 20 has 2 tens and 0 ones.
• The remaining columns depend on the numbers chosen by the learner.

4. Compare Numbers

1. 20 > 18
2. 15 < 20
3. 20 = 20
4. 19 < 20
5. 20 > 12
6. 17 < 20

5. Addition to 20

1. 15
2. 15
3. 20
4. 18
5. 19
6. 20
7. 10
8. 7
9. 4
10. 13

6. Subtraction from 20

1. 19
2. 15
3. 10
4. 10
5. 8
6. 10

7. Real-World Math

1. 12 + 8 = 20; 20 apples
2. 20 - 6 = 14; 14 stickers
3. 15 + 5 = 20; 20 passengers

8. Sort the Numbers

1. 11, 14, 16, 18, 20
2. 3, 7, 12, 19, 20
3. 20, 17, 15, 13, 8

Optional Challenge

1. Answers may include 10 + 10 and 12 + 8.
2. Answers may include 20 - 0 and 25 - 5.
3. The numbers are 8 and 12.