Chapter 9.7
Subtraction using Estimation
What You'll Learn
Round numbers to the nearest ten or hundred to simplify subtraction
Estimate differences between numbers up to 1000 using rounding strategies
Apply place value understanding to make reasonable approximations
Determine when estimation is more efficient than exact calculation
What You'll Practice
1
Rounding two-digit and three-digit numbers before subtracting
2
Estimating differences for numbers up to 1000
3
Comparing estimated answers to check reasonableness
Why This Matters
Estimation helps you quickly check if your answers make sense and solve real-world problems faster. Whether you're calculating change at a store, measuring ingredients, or budgeting money, estimating differences lets you make smart decisions without needing exact numbers every time.
This Unit Includes
Practice exercises
Skills
Estimation
Rounding
Subtraction
Place Value
Mental Math
Number Sense
GA Curriculum Aligned
