Lesson 15: Problem Solving - 1

For Grade 5 Students (Ages 10-11) - Let's put our math skills to the test!

What we will learn today:

In this lesson, you will learn to:

  • Read and understand word problems carefully.
  • Identify the key information and what is being asked.
  • Choose the correct mathematical operation (addition, subtraction, multiplication, or division).
  • Solve multi-step problems.
  • Present your answers clearly.

Steps for Problem Solving

Solving word problems can be easy if you follow these steps:

  1. Understand the Problem: Read the problem carefully. What information is given? What are you asked to find?
  2. Plan Your Solution: Decide which operation(s) you need to use (add, subtract, multiply, divide). Sometimes you might need more than one step!
  3. Solve the Problem: Carry out your plan. Show your working clearly.
  4. Check Your Answer: Does your answer make sense? Is it reasonable? You can use the opposite operation to check.

Practice Problems

Read each problem carefully and solve it. Write your answers in the boxes provided.

Problem 1: Addition and Subtraction

  1. A fruit seller had $1250$ apples. He bought $875$ more apples. If he sold $1500$ apples, how many apples are left?

Problem 2: Multiplication and Division

  1. A box contains $15$ packets of biscuits. Each packet has $10$ biscuits. If these biscuits are shared equally among $5$ children, how many biscuits does each child get?

Problem 3: Time

  1. A train left Colombo at $8:15$ AM and arrived in Kandy at $11:45$ AM. How long did the journey take?

Problem 4: Length and Distance

  1. A rope is $5$ meters long. Another rope is $250$ centimeters long. What is the total length of both ropes in centimeters?

Problem 5: Money

  1. You have Rs. $500$. You buy a pen for Rs. $75.50$ and a notebook for Rs. $120.25$. How much money do you have left?

Answers to Practice Problems

Let's check your answers!

  1. Problem 1: Addition and Subtraction

    • Apples initially: $1250$
    • Apples bought: $875$
    • Total apples: $1250 + 875 = 2125$
    • Apples sold: $1500$
    • Apples left: $2125 - 1500 = 625$ apples.

  2. Problem 2: Multiplication and Division

    • Total packets: $15$
    • Biscuits per packet: $10$
    • Total biscuits: $15 \times 10 = 150$
    • Number of children: $5$
    • Biscuits per child: $150 \div 5 = 30$ biscuits.

  3. Problem 3: Time

    • From $8:15$ AM to $11:15$ AM is $3$ hours.
    • From $11:15$ AM to $11:45$ AM is $30$ minutes.
    • Total journey time: $3$ hours $30$ minutes.

  4. Problem 4: Length and Distance

    • First rope: $5$ meters = $5 \times 100 = 500$ cm
    • Second rope: $250$ cm
    • Total length: $500$ cm + $250$ cm = $750$ cm.

  5. Problem 5: Money

    • Money spent on pen: Rs. $75.50$
    • Money spent on notebook: Rs. $120.25$
    • Total money spent: Rs. $75.50 + 120.25 = 195.75$
    • Money initially had: Rs. $500.00$
    • Money left: Rs. $500.00 - 195.75 = 304.25$ (Rs. $304$ and $25$ cts.)

You've completed Lesson 15!

Fantastic job, Math Lanka students! You've successfully applied your math skills to solve various problems. Problem-solving is a crucial skill, and with practice, you'll become a master!

Next Lesson
Previous Lesson Next Lesson