Topicm4f50caadfabc01bf_1528449000663_0Topic

Metric units of length

Levelm4f50caadfabc01bf_1528449084556_0Level

Second

Core curriculumm4f50caadfabc01bf_1528449076687_0Core curriculum

VII. Lines and line segments. The student:

4) measures a line segment with 1 mm accuracy;

XII. Practical calculations. The student:

6) converts and uses appropriately units of lengthunits of lengthunits of length: millimetre, centimetre, decimetre, metre, kilometre.

Timingm4f50caadfabc01bf_1528449068082_0Timing

45 minutes

General objectivem4f50caadfabc01bf_1528449523725_0General objective

Reading and interpreting data presented in various forms and processing it.

Specific objectivesm4f50caadfabc01bf_1528449552113_0Specific objectives

1. Measuring line segments with 1 mm accuracy.

2. Converting units of length: millimetre, centimetre, decimetre, metremetremetre, kilometre.

3. Communicating in English, developing basic mathematical, computer and scientific competences, developing learning skills.

Learning outcomesm4f50caadfabc01bf_1528450430307_0Learning outcomes

The Student:

- measures line segments with 1 mm accuracy,

- converts units of length: millimetre, centimetre, decimetre, metre, kilometre.

Methodsm4f50caadfabc01bf_1528449534267_0Methods

1. Discussion.

2. JIGSAW.

Forms of workm4f50caadfabc01bf_1528449514617_0Forms of work

1. Individual work.

2. Group work.

Lesson stages

Introductionm4f50caadfabc01bf_1528450127855_0Introduction

Discussion – students name length units they already know. They talk about situations where we can use them. They think about kinds of objects we can use to measure lengthlengthlength or heightheightheight. They notice that lengths of the same line segments can be given in different units.

Procedurem4f50caadfabc01bf_1528446435040_0Procedure

The teacher divides students into four groups. Their task is to collect information obtained in the discussion.

Information students should present:
- most common units of lengthunits of lengthunits of length are: millimetremillimetremillimetre, centimetrecentimetrecentimetre, decimetredecimetredecimetre, metremetremetre, kilometrekilometrekilometre,
- big lengths are given in kilometres or metres and smaller in centimetres, decimetres or millimetres,
- in order to measure short objects or line segments, we use the ruler. We can also use the tape measure or the callipers,
- same distances can be given in different units,
- to compare lengths or distances or heights, they need to be given in the same unit,
- we can convert the units of length using the relations between them.

Students work individually, using computers. Their task is to get to know the interactive illustration, that presents converting the units of length.

[Interactive graphics]

Conclusions:

- we can convert the units using the relations between them:
1 km = 1000 m,
1 m = 100 cm,
1 m = 10 dm,
1 dm = 10 cm,
1 m = 100 cm,
1 cm = 10 mm.

Students use the JIGSAW method and use obtained information in the exercises.

The teacher divides students into 3 persons groups. Each member of the group gets different task from the tasks below. After solving the tasks, students gather in groups that were doing the same task. They discuss the solutions and clarify any doubts. Then, they return to the initial groups and present the solutions to other members.

Task 1

Insert proper numbers in the dotted spaces.
a) 15 cm = …….. mm
b) 4890 cm = …….dm
c) 500000 m = ………..km
d) 6520000 m = ………..cm
e) 32 dm = ……….mm
f) 52 m = ………. dm
g) 2 km = ……..cmm4f50caadfabc01bf_1527752256679_0Insert proper numbers in the dotted spaces.
a) 15 cm = …….. mm
b) 4890 cm = …….dm
c) 500000 m = ………..km
d) 6520000 m = ………..cm
e) 32 dm = ……….mm
f) 52 m = ………. dm
g) 2 km = ……..cm

Task 2

Using the formula, write the given lengthlengthlength in the form of monomial expression.

Formula:

3 m 43 cm = 300 cm + 43 cm = 343 cm

a) 25 m 58 cm
b) 3km 254 m
c) 15 dm 65 cm
d) 5m 15 cm 5mm

Task 3

Using the formula, write the given length in the form of binomial expression.

Formula:

520 cm = 500 cm + 20 cm = 5 m 20 cm

a) 2547 m
b) 680 m
c) 365 cm
d) 540 dm

The teacher grades the students’ work and clarifies doubts.

An extra task:

In order to determine the length of various screens, we often use the unit called an inch. 1 inch is about 25 mm. Writing that the TV has 46 inches means that the length of the diagonal of this TV is 46 inches. Calculate how many mm that is. Give the length of the diagonal in the form of binomial expression.

Lesson summarym4f50caadfabc01bf_1528450119332_0Lesson summary

Students do the revision exercises. Then together they sum‑up the classes, by formulating the conclusions to memorise.

- most common units of length are: millimetre, centimetre, decimetre, metre, kilometre.
- same distances can be given in different units.
- we can convert the units using the relations between them:
1 km = 1000 m
1 m = 100 cm
1 m = 10 dm
1 dm = 10 cm
1 m = 100 cm
1 cm = 10 mm.m4f50caadfabc01bf_1527752263647_0- most common units of length are: millimetre, centimetre, decimetre, metre, kilometre.
- same distances can be given in different units.
- we can convert the units using the relations between them:
1 km = 1000 m
1 m = 100 cm
1 m = 10 dm
1 dm = 10 cm
1 m = 100 cm
1 cm = 10 mm.

Selected words and expressions used in the lesson plan

units of lengthunits of lengthunits of length

metremetremetre

lengthlengthlength

widthwidthwidth

heightheightheight

distancedistancedistance

kilometrekilometrekilometre

centimetrecentimetrecentimetre

millimetremillimetremillimetre

decimetredecimetredecimetre