Page 227 - NUMINO TG_3A
P. 227
Activity 2 Addition and Subtraction in Mirrors
jOb ective Use properties of symmetry to add and subtract numbers.
1. Textbook Instructions Activity 2 Addition and Subtraction in Mirrors
1. Have students solve the subtraction and 1 . Addition and subtraction of digital numbers are reflected in a mirror.
addition problems by looking at the images
that would show in the mirrors. Solve the problem without using a mirror.
First, have them write down the problems in
the blank and then solve the problems. a.
Have students understand that when they -
reflect number 2 on a mirror, it shows
number 5 and vice versa. - =3
Make sure students do not use mirrors b.
when solving the problems. Have them use
mirrors only to check their answers. + = 52
+
c.
++ = 56
130
2. Build Understanding
Problem: Solve the problem without using a mirror. Solution:
++ ++
Answer: 36 45 81
210 NUMINO Teacher s Guide
jOb ective Use properties of symmetry to add and subtract numbers.
1. Textbook Instructions Activity 2 Addition and Subtraction in Mirrors
1. Have students solve the subtraction and 1 . Addition and subtraction of digital numbers are reflected in a mirror.
addition problems by looking at the images
that would show in the mirrors. Solve the problem without using a mirror.
First, have them write down the problems in
the blank and then solve the problems. a.
Have students understand that when they -
reflect number 2 on a mirror, it shows
number 5 and vice versa. - =3
Make sure students do not use mirrors b.
when solving the problems. Have them use
mirrors only to check their answers. + = 52
+
c.
++ = 56
130
2. Build Understanding
Problem: Solve the problem without using a mirror. Solution:
++ ++
Answer: 36 45 81
210 NUMINO Teacher s Guide
