1- & 2-Digit (3 Addends)

Teaching Notes

Have students circle pairs that make ten or hundred.

Common Mistakes

• Ignoring make-ten pairs.
• Incorrectly combining 1- and 2-digit numbers.
• Losing track of sums mentally.
• Not checking for friendly sums first.

Differentiation

Discussion Questions

• What strategies did you use today?
• How do 'make ten' pairs help?
• Can you find different ways to add?
• When is mental math useful in daily life?

Skill Cluster

Addition Strategies

Estimated Time

12 minutes

Skills Practiced

Prerequisites

• 3
• Adding 2 single-digit numbers
• Number bonds to 10
• Adding 2-digit numbers without regrouping

Next Steps

• Adding multiple 2-digit numbers with regrouping
• Adding 3-digit numbers mentally
• Estimating sums of multiple numbers
• 3-Digit (3 Addends) - Mental Math
• Adding Multiple 2-Digit Numbers - Regrouping
• Adding 1- & 2-Digit Numbers - Missing Addends