L003 · Allow 10–15 minutes for learners ready to move on. Answers are available after an attempt.
Round 0.004976 to two significant figures and estimate 397×0.049.
0.0050; estimate 400×0.05=20.
A number rounds to 3.50 to two decimal places. Give its interval and explain the excluded endpoint.
3.495≤x<3.505; 3.505 rounds to 3.51.
Lesson L003: Place value, decimals and estimation
Objective: Use place value to scale and compare decimals, round to stated accuracy, and judge whether a calculation is reasonable.
60-minute structure: 0-7 Connect & Check; 7-14 Share; 14-25 Present/model; 25-44 Apply route choice/practice; 44-52 independent exam-style check; 52-60 Recall & Review, WWW/EBI and next step.
I selected an efficient numerical method, showed the key steps clearly and checked the sign, size or accuracy of my answer.
I will make the place-value, sign or operation decision explicit and use estimation or an inverse calculation to check a fresh question.
Stretch: Round 0.004976 to two significant figures and estimate 397×0.049.
Deep challenge: A number rounds to 3.50 to two decimal places. Give its interval and explain the excluded endpoint.