Guess Two Numbers Based on Sum and Difference

Become a number detective and solve the mystery of missing numbers!

The Number Detective Challenge

Imagine you're a detective trying to find two secret numbers!
You know how much they add up to (their sum) and how much bigger one is than the other (their difference). With these two clues, you can always find the mystery numbers!

How to Solve Number Mysteries

1️⃣ Add the sum and difference together

2️⃣ Divide by 2 to find the bigger number

3️⃣ Subtract the difference from the bigger number to find the smaller one

A B difference sum

Let's Solve Some Mysteries!

Example 1: The Cookie Mystery

Emma and Liam baked cookies together. The total number of cookies is 14, and Emma baked 2 more than Liam. How many did each bake?

? + ? = 14 (sum)
? - ? = 2 (difference)

1️⃣ Add sum and difference: 14 + 2 = 16

2️⃣ Divide by 2 for bigger number: 16 ÷ 2 = 8 (Emma's cookies)

3️⃣ Subtract difference: 8 - 2 = 6 (Liam's cookies)

Answer: Emma baked 8 cookies and Liam baked 6 cookies!

Example 2: The Pet Store Puzzle

A pet store has dogs and cats. There are 20 animals total, and there are 6 more dogs than cats. How many dogs and cats are there?

🐶 + 🐱 = 20 (sum)
🐶 - 🐱 = 6 (difference)

1️⃣ Add sum and difference: 20 + 6 = 26

2️⃣ Divide by 2 for bigger number: 26 ÷ 2 = 13 (dogs)

3️⃣ Subtract difference: 13 - 6 = 7 (cats)

Answer: There are 13 dogs and 7 cats in the store!

Parent Tips 🌟

  • Use real objects: Try this with small toys or snacks to make it hands-on. For example, use 14 grapes (total) with 2 more on one side to demonstrate the cookie problem.
  • Make it a game: Create number mystery challenges where your child plays detective to find the missing numbers.
  • Connect to everyday life: Point out real situations where we know totals and differences - like ages of siblings, heights of plants, or scores in games.

Ready for More Math Fun?

Continue your child's math journey with our interactive lessons and games!

Download iMath App