Objective

By the end of this lesson, you will be able to solve mixed operation problems involving 3-digit numbers.

Materials and Prep

• Pencil
• Blank paper
• Calculator (optional)

Before starting this lesson, make sure you are comfortable with addition, subtraction, and multiplication of 2-digit numbers.

Activities

1. Activity 1: Addition and Subtraction Race

   Challenge yourself to solve 5 addition and subtraction problems as quickly as possible. Use a timer to track your progress. Write down the problems and their solutions on a piece of paper.

2. Activity 2: Multiplication Mystery

   Think of a 3-digit number. Multiply it by a 1-digit number of your choice. Write down the multiplication problem and solve it. Then, reveal the original 3-digit number. Can you figure out what number you started with?

3. Activity 3: Problem-solving Challenge

   Create your own mixed operation word problem using 3-digit numbers. Write it down and solve it. Then, challenge a family member or friend to solve your problem.

Talking Points

• When we add two numbers, we put them together to find the total. For example, if we have 234 apples and we add 56 more apples, how many apples do we have in total?

  Say: "Let's add 234 and 56 together. The answer is 290. So, we have a total of 290 apples."

• Subtraction is the opposite of addition. It helps us find the difference between two numbers. For example, if we have 290 apples and we eat 56 apples, how many apples do we have left?

  Say: "Let's subtract 56 from 290. The answer is 234. So, we have 234 apples left."

• Multiplication is a quicker way of adding numbers. It helps us find the total when we have groups of the same number. For example, if we have 3 groups of 100 apples, how many apples do we have in total?

  Say: "Let's multiply 3 by 100. The answer is 300. So, we have a total of 300 apples."

• When we solve mixed operation problems, we need to follow the order of operations. First, we do any calculations inside parentheses. Then, we perform multiplication and division from left to right. Finally, we do addition and subtraction from left to right.

  Say: "Remember, we always solve problems in the correct order. Let's look at this example: 100 + 50 - (30 x 2). First, we do the multiplication inside the parentheses. 30 x 2 is 60. Then, we add 100 and 50. The sum is 150. Finally, we subtract 60 from 150. The answer is 90."