Page 29 - NUMINO TG_3A
P. 29
Challenge Mirror Numbers
jOb ective Use a mirror to find a number that has symmetry.
1. Textbook Instructions Challenge Mirror Numbers
Place a mirror in the middle of a number and Kate placed a mirror in the middle of the 4-digit number, 1001.
tell students about numbers that have Kate looked at the number in the mirror.
symmetry. Surprisingly, she saw the same number, 1001, in the mirror.
When I place a mirror in the middle of
1,001, does the shape change? No.
How does the shape of the number in the
mirror look when you compare it to the
real number? They look the same. They
completely overlap each other.
Since the numbers completely overlap
each other when you fold it along the
middle line, where the mirror is placed,
what does this shape have? It has
symmetry.
This number is called a mirror number.
A number that can be reflected in half and have both halves match
exactly has symmetry.
10 01 23
4567
2. Build Understanding 89
For students who are having difficulty finding mirror numbers,
have them work with numbers from 0 to 9. Have them find
numbers that do not change when they place a mirror on the
sides (0, 1, 8). Then have students make mirror numbers
using numbers zero, one, and eight.
012 NUMINO Teacher s Guide
jOb ective Use a mirror to find a number that has symmetry.
1. Textbook Instructions Challenge Mirror Numbers
Place a mirror in the middle of a number and Kate placed a mirror in the middle of the 4-digit number, 1001.
tell students about numbers that have Kate looked at the number in the mirror.
symmetry. Surprisingly, she saw the same number, 1001, in the mirror.
When I place a mirror in the middle of
1,001, does the shape change? No.
How does the shape of the number in the
mirror look when you compare it to the
real number? They look the same. They
completely overlap each other.
Since the numbers completely overlap
each other when you fold it along the
middle line, where the mirror is placed,
what does this shape have? It has
symmetry.
This number is called a mirror number.
A number that can be reflected in half and have both halves match
exactly has symmetry.
10 01 23
4567
2. Build Understanding 89
For students who are having difficulty finding mirror numbers,
have them work with numbers from 0 to 9. Have them find
numbers that do not change when they place a mirror on the
sides (0, 1, 8). Then have students make mirror numbers
using numbers zero, one, and eight.
012 NUMINO Teacher s Guide
