📘 Improve flexible thinking with rounding, compatible numbers, and estimation. 📌 **Topics Included:** • Approximate powers of 10 mentally • Compatible numbers for division • Compatible numbers for subtraction • Estimating products • Estimating sums • Estimating with fractions • Estimating with mixed numbers • Estimating with percents • Halving and doubling strategy • Mental division using fact families • Multiplying by 25 mentally • Rounding to subtract quickly • Subtraction by making tens • S