Page 229 - NUMINO TG_3A

Activity 3 Number of Dots in Mirrors

jOb ective Use properties of symmetry to find the total number of dots reflected on the mirror.

1. Textbook Instructions Activity 3 Number of Dots in Mirrors

Have students understand that the number Learn how the number of dots changes according to the placement of the
of dots they see will depend on where they mirror and the direction they are viewed.
place the mirror and the direction in which
the image is reflected on the mirror.

The arrow indicates the direction in which

the image is reflected on the mirror. Make mirror Number of dots: 2

sure students know this before solving the

problems.

Refer to .

mirror Number of dots: 4

1. Have students find the number of dots that 1 . Count the number of dots on the paper and the mirror in the direction
appear according to where the mirror is
placed. of the arrow. Use a mirror to check your answer.

Students will realize that the number of dots What you need: Mirror
on the paper and the number of dots on the
mirror are equal. a. b.

mirror mirror

Number of dots: 8 Number of dots: 6

132

2. Build Understanding

The Direction in Which the Image is Reflected on the Mirror Example: 1b.
The arrow shows the direction in which the image is reflected 1a.
on the mirror. The dots that are circled should be reflected on mirror
the mirror.

mirror

212 NUMINO Teacher s Guide