Estimating with Rounding Word Problems

Teaching Notes

Have students justify the place value they chose for rounding.

Vocabulary

Estimate: Find an approximate answer.

Round: Change a number to a simpler value.

Common Mistakes

• Rounding one number but not the other
• Using exact values instead of rounded
• Rounding to an inappropriate place
• Calculating precisely instead of estimating
• Forgetting to show rounded numbers
• Misinterpreting word problem context

Differentiation

Discussion Questions

• Why might rounding to hundreds be better than tens here?
• When is it helpful to estimate instead of calculate exactly?
• How do you choose which place value to round to?
• Can two people estimate the same problem differently?
• Why is showing rounded numbers important?

Extension Activities

• Estimate before solving exactly and compare error magnitudes

Parent Tip

Ask your child to estimate the total cost of two items at the store.

Skill Cluster

Number Sense & Operations

Estimated Time

15 minutes

Skills Practiced

Prerequisites

• 734
• 735
• 736
• Place Value to Thousands
• Rounding Whole Numbers
• Solving Basic Word Problems

Next Steps

• Estimating with Decimals
• Multi-Step Estimation Problems
• Estimating Products and Quotients
• Rounding Whole Numbers to Any Place
• Estimating Sums and Differences
• Multi-Step Word Problems