84 MATHEMATICS 5 CURRICULUM GUIDE 2015 Specific Outcomes MEASUREMENT Suggestions for Teaching and Learning Students will be expected to: Shape and Space (Measurement) 5SS2 Demonstrate an understanding of measuring length (mm and km) by: •
selecting and justifying referents for the unit mm •
modelling and describing the relationship between mm and cm units, and between mm and m units •
selecting and justifying referents for the unit km •
modelling and describing the relationship between m and km units. [C, CN, ME, PS, R, V] In Grade 3, students measured lengths in cm and m. In Grade 5,
students will continue to develop skills with cm and m units, as well as
being introduced to mm and km units.
The introduction to millimetres should take place after students have
had additional experience using centimetres. A good way to introduce
millimetres is to look at objects that are between centimetres; something,
that is 25 mm, for example, is between two and three cm.
When discussing centimetres, use an overhead ruler which has only
centimetres marked (if possible). Once students work with centimetres,
introduce the ruler that includes the markings for centimetres and
millimetres.
Achievement Indicators: 5SS2.1 Show that 10 millimetres is equivalent to 1 centimetre using concrete materials. It can easily be shown on a centimetre ruler that 1cm = 10 mm or that
30 mm = 3 cm.
Students will require many experiences comparing one unit of
measurement to another. Have students make some curved paths on the
floor with masking tape. Use a rope to measure the path, then stretch
out the rope and measure it in mm. Ask the students to decide what the
measure will be in a different unit such as m or cm.
Possible shapes:
5SS2.2 Show that 1 000 millimetres is equivalent to 1 metre using concrete materials. A metre stick is divided into centimetres. Students should analyze a
metre stick to see that 100 cm = 1 metre.
Since they know that 1 cm = 10 mm, it follows that 1 metre (100 cm)
has 1 000 mm.
Using the metre stick, students can mark off sets of 10 mm (1cm) again
realizing that 10 mm x 100 = 1 000 mm.
While discussing a millimetre, students will realize that it is a very tiny
linear measurement. Ask students to draw 1 mm on paper using a ruler.
They could discover referents by brainstorming objects that would be
that tiny. Suggestions might include: thickness of a fingernail, width
of an eyelash, head of a straight pin, a fraction of a mosquito leg, the
thickness of a credit card or a stack of 10 sheets of paper.
5SS2.3 Provide examples of when millimetres are used as the unit of measure.