Math3-5
Mental Math with the Compensation Strategy, Grade 4
By Denise L.
A practice worksheet for 4th graders that teaches mental addition through the compensation strategy: round one addend to a friendly number, add, then subtract the extra amount. It builds number sense and mental math fluency with worked examples, a number line, and practice problems like 119 + 126.
Customize for your classroom
Teacher Guide & Tips
- Introduce the key terms (friendly number and compensation) and work through Example 1 together before students try problems independently, using a 20-30 minute mini-lesson.
- Discussion question: Why does rounding 48 up to 50 make the problem easier, and how do we know to subtract 2 at the end?
- Scaffold for struggling readers: have them use the number line graphic to physically count the jump from the rounded number back to the original, and begin with problems where one addend is within 5 of a friendly number.
- Extension for advanced students: ask them to try compensation with numbers that need rounding down (such as 52 + 37 using 50) and to explain when rounding up or down is more efficient.
- Plan roughly 35-45 minutes for the full packet, which works well as independent practice or partner work after the lesson.
Math3-5
Mental Math with the Compensation Strategy, Grade 4
By Denise L.
A practice worksheet for 4th graders that teaches mental addition through the compensation strategy: round one addend to a friendly number, add, then subtract the extra amount. It builds number sense and mental math fluency with worked examples, a number line, and practice problems like 119 + 126.
Customize for your classroom
Teacher Guide & Tips
- Introduce the key terms (friendly number and compensation) and work through Example 1 together before students try problems independently, using a 20-30 minute mini-lesson.
- Discussion question: Why does rounding 48 up to 50 make the problem easier, and how do we know to subtract 2 at the end?
- Scaffold for struggling readers: have them use the number line graphic to physically count the jump from the rounded number back to the original, and begin with problems where one addend is within 5 of a friendly number.
- Extension for advanced students: ask them to try compensation with numbers that need rounding down (such as 52 + 37 using 50) and to explain when rounding up or down is more efficient.
- Plan roughly 35-45 minutes for the full packet, which works well as independent practice or partner work after the lesson.