Age Problem: David and his sister

easyGrade 3-5age difference

The Problem

David is 16 years old. His sister is 6 years younger than David. How old is his sister?

Answer:

10 years old

Key Information

  • David is 16 years old
  • his sister is 6 years younger

Step-by-Step Solution

1

Identify the given information

David's age = 16 years, Age difference = 6 years
2

Set up the equation

his sister's age = David's age - 6
3

Substitute values

his sister's age = 16 - 6
4

Calculate

16 - 6 = 10
5

Final answer

his sister is 10 years old

Common Mistakes to Avoid

  • Adding instead of subtracting the age difference
  • Confusing who is older or younger

Helpful Tips

  • Read the problem carefully to identify who is older
  • Subtract when someone is younger, add when they are older

Real-World Application

Age problems help understand relationships between ages and develop subtraction skills.

Related Topics:

agesubtractionword problemsbasic math

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