Teacher GuideWeek 17Measurement: Length & Comparing — Teacher Guide
Monday: Measuring with an Inch Ruler
1Warm-up
1. 12, 8, 15, 7
2Ruler Basics
1. Emphasize lining up the 0 end; common error is starting at 1
3Measure in Inches
1. A=2 in, B=4 in, C=3 in, D=5 in
4Number Talk
1. D is longer — it stretches farther; pencil is about 3 inches longer (7−4)
5Challenge
1. Any real objects; check ruler technique, not exactness

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Tuesday: Estimating & Measuring in Centimeters
1Warm-up
1. 16, 7, 15, 8
2Centimeters
1. Fingertip ≈ 1 cm benchmark
3Estimate First
1. A=5 cm, B=9 cm, C=3 cm, D=7 cm; praise estimates within 2 cm
4Best Unit
1. ant=cm, door=feet (or meters), shoe=inches, soccer field=meters
5Word Problem
1. 30−12 = 18 cm

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Wednesday: Measuring Twice
1Warm-up
1. 7, 14, 5, 13
2Measure Twice
1. A: 2 in / 4 cm; B: 4 in / 8 cm; C: 3 in / 6 cm (printed scale)
3Number Talk
1. Centimeters are smaller units, so it takes MORE of them to cover the same line
4How Much Longer
1. 17 cm, 26 inches, 33 cm, 48 inches
5Create Your Own
1. Any line; celebrate estimates within 1 inch of 4

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Thursday: Length Word Problems
1Warm-up
1. 18, 9, 13, 9
2Estimate First (Real Objects)
1. Paper width ≈ 8.5 in; other answers vary — check reasonableness
3Word Problems
1. 63−38 = 25 cm added; 72−45 = 27 inches empty; 34+19 = 53 inches
4Two Ways
1. 50−23 = 27 cm; counting up: 23→30 is 7, 30→50 is 20, total 27
5Create Own
1. Accept student problems with correct solution

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Friday: Review & Self-Check
1Warm-up
1. 7, 17, 8, 13
2Estimate First
1. A=4 cm, B=8 cm (printed scale)
3Mixed Review
1. 5 inches taller; meters; 13 cm; 24 inches
4Word Problem
1. 47+29 = 76 cm
5Self-Check
1. Accept student self-assessment and reflection