Page 35 - NUMINO TG_6A
P. 35
02Unit Which Is the Greatest?
jOb ective Learn about common factors and the greatest common factor.
1. Textbook Instructions 02 Which Is the Greatest?
This unit introduces students to common Learn about the common factors.
factors and the closely related concept of
common multiples. Begin by ensuring that Numbers that are factors of two or more numbers are called
students understand factors as numbers that common factors.
“go evenly” into a given number without a
remainder, then develop the idea of common Find the common factors of the given numbers and circle them.
factors shared by two numbers.
Common factors of 4 and 8
Lead students through the exercises, 12345678
beginning with the sample. In each exercise
the common factors are circled, starting with Common factors of 5 and 30 Common factors of 10 and 20
the smallest. Every integer has 1 as a factor, 123456 123456
so 1 is a given. Then proceed through each 7 8 9 10 11 12 7 8 9 10 11 12
integer, asking whether it goes evenly into the 13 14 15 16 17 18 13 14 15 16 17 18
two numbers specified.
Does 2 go into 5? Does 3? Does 4? In each
case the answer is no, and there is no need
to test whether it goes evenly into 30.
Common factors of 12 and 24 Common factors of 16 and 32
123456 123456
7 8 9 10 11 12 7 8 9 10 11 12
13 14 15 16 17 18 13 14 15 16 17 18
10
2. Build Understanding
In each of these exercises the second number is a multiple of the first, so the common factors will include at
least 1 and the first number itself, e.g. 5.
All of these exercises except for the first (5 and 30) have several intermediate common factors as well.
Students may notice that two even numbers will always have 2 as a common factor, while no odd number
will have 2 as a factor.
If students do not notice this, point it out to them.
018 NUMINO Teacher s Guide
jOb ective Learn about common factors and the greatest common factor.
1. Textbook Instructions 02 Which Is the Greatest?
This unit introduces students to common Learn about the common factors.
factors and the closely related concept of
common multiples. Begin by ensuring that Numbers that are factors of two or more numbers are called
students understand factors as numbers that common factors.
“go evenly” into a given number without a
remainder, then develop the idea of common Find the common factors of the given numbers and circle them.
factors shared by two numbers.
Common factors of 4 and 8
Lead students through the exercises, 12345678
beginning with the sample. In each exercise
the common factors are circled, starting with Common factors of 5 and 30 Common factors of 10 and 20
the smallest. Every integer has 1 as a factor, 123456 123456
so 1 is a given. Then proceed through each 7 8 9 10 11 12 7 8 9 10 11 12
integer, asking whether it goes evenly into the 13 14 15 16 17 18 13 14 15 16 17 18
two numbers specified.
Does 2 go into 5? Does 3? Does 4? In each
case the answer is no, and there is no need
to test whether it goes evenly into 30.
Common factors of 12 and 24 Common factors of 16 and 32
123456 123456
7 8 9 10 11 12 7 8 9 10 11 12
13 14 15 16 17 18 13 14 15 16 17 18
10
2. Build Understanding
In each of these exercises the second number is a multiple of the first, so the common factors will include at
least 1 and the first number itself, e.g. 5.
All of these exercises except for the first (5 and 30) have several intermediate common factors as well.
Students may notice that two even numbers will always have 2 as a common factor, while no odd number
will have 2 as a factor.
If students do not notice this, point it out to them.
018 NUMINO Teacher s Guide
