Year 5 Maths: Write Variable Expressions: Word Problems

Introduction to Variable Expressions

Today, we’re going to learn about variable expressions. This might sound tricky, but don’t worry! We will break it down into simple parts.

What is a Variable?

A variable is a letter that stands for a number we don’t know yet. It can be any letter, but we often use x, y, or n. For example, if I say x is the number of apples you have, x can stand for any number of apples!

What is an Expression?

An expression is a combination of numbers, variables, and operations (like adding or subtracting). For example, 3 + x means “3 plus some number of apples.”

Why Do We Use Variable Expressions?

We use variable expressions to help us solve problems when we don’t know all the numbers. They help us write a math problem in a way that we can work with.

Writing Variable Expressions from Word Problems

When you read a word problem, you can turn it into a variable expression. Here are some simple steps to follow:

1. Read the Problem Carefully: Understand what it is asking.
2. Identify the Unknown: What do we need to find out? This will be our variable.
3. Use Symbols for Operations:
   • Add: Use +
   • Subtract: Use –
   • Multiply: Use × or a dot (•)
   • Divide: Use ÷
4. Write the Expression: Combine the variable and numbers using the operations.

Examples

1. Example 1: “I have x apples. I buy 5 more apples.”
   • Expression: x + 5
2. Example 2: “There are y birds in the tree. 3 fly away.”
   • Expression: y – 3
3. Example 3: “I score n points in a game. I score 10 more points.”
   • Expression: n + 10

Key Rules

• Always identify the variable first.
• Use clear operations to express the relationship between numbers and variables.
• Make sure your expression matches what the problem is asking.

Tips and Tricks

• Underline or highlight key information in the problem.
• Write down the variable you have chosen.
• Don’t rush! Take your time to think about what the problem means.

Practice Questions

Now, let’s see how well you can write variable expressions! Below are some questions for you to try.

Easy Level Questions (1-20)

1. I have x candies. I eat 2. What is the expression?
2. There are y books on the shelf. I add 4 more books. Write the expression.
3. I have n stickers. I give away 3. What is the expression?
4. There are a flowers in the garden. 5 flowers bloom. Write the expression.
5. My sister has b toys. She buys 6 more. What is the expression?
6. I see c birds flying. 2 fly away. Write the expression.
7. There are d cookies on the plate. I eat 1. What is the expression?
8. I have e dollars. I find 10 more. Write the expression.
9. There are f players in the game. 3 leave. What is the expression?
10. I have g marbles. I lose 2. Write the expression.
11. My friend has h balloons. 4 pop. What is the expression?
12. There are i apples in the basket. I add 3. Write the expression.
13. I have j pictures. I give away 5. What is the expression?
14. There are k fish in the pond. I catch 1. Write the expression.
15. I see l stars. 3 disappear. What is the expression?
16. My brother has m comics. He buys 2 more. Write the expression.
17. There are n cupcakes. I eat 4. What is the expression?
18. I have o cars. I get 5 more. Write the expression.
19. There are p pencils in the box. I break 2. What is the expression?
20. I have q tickets. I give away 1. What is the expression.

Medium Level Questions (21-40)

21. I have x apples. I give away y apples. Write the expression.
22. There are 10 students in class. If x more come, what is the expression?
23. I have a books. I borrow b more. Write the expression.
24. There are c cars in the parking lot. 5 are red. What is the expression?
25. I have d stickers. I lose e. Write the expression.
26. There are f dogs. 2 run away. What is the expression?
27. I find g coins. I lose h. Write the expression.
28. There are i eggs. I bake with j. Write the expression.
29. I score k points in a game. I score l more. Write the expression.
30. There are m flowers. n bloom. Write the expression.
31. I have o marbles. I give away p. Write the expression.
32. There are q chairs in the room. 3 are broken. What is the expression?
33. I have r videos. I watch s. Write the expression.
34. There are t birds in the air. 4 land. What is the expression?
35. I see u stars. I can count v. Write the expression.
36. I have w toys. I buy x more. Write the expression.
37. There are y fish in the tank. I feed z. What is the expression?
38. I have a letters. I send b. Write the expression.
39. There are c cookies on the plate. I eat d. Write the expression.
40. I have e cards. I trade f. Write the expression.

Hard Level Questions (41-60)

41. I have x apples and y bananas. What is the expression for the total fruit?
42. I earn a pounds a week. If I save b pounds, what is the expression for my savings?
43. There are c students in the class. d leave for a trip. What is the expression for students left?
44. I read e pages today and f pages tomorrow. What’s the expression for total pages read?
45. I have g stickers. I give h to my friend. Write the expression for stickers left.
46. There are i cars in the garage. I see j more parked outside. What is the expression?
47. I have k marbles, and I lose l. Write the expression for the remaining marbles.
48. There are m flowers in the garden, and n are wilting. Write the expression.
49. I bake o cookies and give p away. What is the expression for cookies left?
50. I have q sports cards, and I trade r with my friend. Write the expression.
51. My collection has s stamps. I find t more. What is the expression for the total?
52. There are u fish in a tank. I catch v fish. What’s the expression for fish left?
53. I read w books this month. If I read x next month, what’s the expression?
54. I save y pounds each week. If I have z pounds saved, write the expression.
55. I have a apples and eat b. What is the expression for apples left?
56. There are c kids at a party. If d leave, what is the expression for kids remaining?
57. I collect e coins and find f. What is the expression for total coins?
58. There are g puppies in a basket. If h are adopted, what’s the expression for puppies left?
59. I have i stickers and give j to my friend. Write the expression for stickers remaining.
60. I bake k cupcakes and sell l. What is the expression for cupcakes left?

Answers and Explanations

Easy Level Answers

1. ( x – 2 )
2. ( y + 4 )
3. ( n – 3 )
4. ( a + 5 )
5. ( b + 6 )
6. ( c – 2 )
7. ( d – 1 )
8. ( e + 10 )
9. ( f – 3 )
10. ( g – 2 )
11. ( h – 4 )
12. ( i + 3 )
13. ( j – 5 )
14. ( k – 1 )
15. ( l – 3 )
16. ( m + 2 )
17. ( n – 4 )
18. ( o + 5 )
19. ( p – 2 )
20. ( q – 1 )

Medium Level Answers

21. ( x – y )
22. ( 10 + x )
23. ( a + b )
24. ( c – 5 )
25. ( d – e )
26. ( f – 2 )
27. ( g – h )
28. ( i – j )
29. ( k + l )
30. ( m + n )
31. ( o – p )
32. ( q – 3 )
33. ( r – s )
34. ( t – 4 )
35. ( u – v )
36. ( w + x )
37. ( y + z )
38. ( a – b )
39. ( c – d )
40. ( e – f )

Hard Level Answers

41. ( x + y )
42. ( a + b )
43. ( c – d )
44. ( e + f )
45. ( g – h )
46. ( c + j )
47. ( k – l )
48. ( m – n )
49. ( o – p )
50. ( q – r )
51. ( s + t )
52. ( u – v )
53. ( w + x )
54. ( y + z )
55. ( a – b )
56. ( c – d )
57. ( e + f )
58. ( g – h )
59. ( i – j )
60. ( k – l )

I hope this lesson helps you understand how to write variable expressions from word problems! Remember, practice makes perfect! Happy learning!