Complete the next ten (215)

Teaching Notes

Essential skill for mental math fluency. Use number lines to visualize jumping to the next ten. Connect to real life: "You have 27 dollars and need 30. How much more?" This builds foundation for making tens strategy in addition.

Vocabulary

Next ten: The closest multiple of ten greater than a number.

Ones digit: The rightmost digit in a number.

Common Mistakes

• Adding to wrong benchmark (e.g., adding to 40 instead of 30)
• Counting all the way up instead of finding difference
• Confusing with rounding
• Not recognizing the next ten
• Miscounting when adding on to reach the next ten
• Confusing the target 'next ten' (e.g., 23 to 30, not 20)
• Difficulty visualizing the 'gap' to the next ten without manipulatives

Differentiation

Discussion Questions

• Why is knowing how to 'make a ten' helpful for adding larger numbers?
• Can you think of a real-life situation where you might need to 'complete the next ten'?
• What strategies do you use to quickly find the missing number?

Extension Activities

• Complete the next hundred.
• Use larger numbers.
• Practice with subtraction.

Parent Tip

Say a number, like 34, and ask 'How many more to make 40?'

Skill Cluster

Number Sense & Operations

Grade Level

1-3

Skills Practiced

Prerequisites

• Basic Math Skills
• Number Bonds to 10
• Counting to 100
• Adding within 20

Next Steps

• Advanced Practice
• Adding 2-Digit Numbers with Regrouping
• Subtracting 2-Digit Numbers with Regrouping
• Mental Addition Strategies