Page 15 - 新思维数学学生用书8 样章

1 Integers

Worked example 1.2

Look at this sequence of subtractions.
3 6 = − 3
−

3 4−= − 1 A sequence is a set of
3 2−= numbers or expressions
−
3 0 = made and written in
3 −− = order, according to some
2
3 −− = pattern.
4
a Copy the sequence and fill in the missing answers.
b Write the next three lines in the sequence.
c Describe any patterns in the sequence.

Answer

a 3 21−=
3 03
−=
3 −− 25
=
3 −− = 7
4
b 3 −− = 9
6
3 −− 811
=
3 −− 10 13
=
c The first number, 3, does not change.
The number being subtracted decreases by 2 each time.
The answer increases by 2 each time.

Exercise 1.2

Think like a mathematician

1 Here is the start of a sequence of multiplications.
−×34 =−12
−× =
33
−× =
32
a Copy the sequence and write six more terms. Use a pattern to fill in the
answers.
b Describe the patterns in the sequence.

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