Page 24 - 新思维数学学生用书6 样章

2.1 Counting and sequences

b Jodi starts to make a table showing the position (shape number) and the term
(total number of rectangles and triangles).

Copy and complete her table.

Position Term

1 3

2
9

12
5

c What is the position-to-term rule for Jodi’s sequence?

d What is the 20th term in the sequence?
Check your answers with your partner.

5 Pablo counts on in quarters.

What are the two missing numbers?
1
1 1 3 1 1 2
4 2 4 2
6 a Write a sequence with steps of constant size in Tip

which the first term is 1 and the fifth term is 1.04.
Beware! The answer
, , , ,
is not 1.1.

b What is the 10th term?
7 Ollie writes a number sequence starting at 15 and counting back in steps of 0.4.

15, 14.6, 14.2, 13.8, …
He says, ‘–1.5 cannot be in my sequence.’

Ollie is correct. How do you know without counting back?

Discuss your answer with your partner.
2
8 Hassan counts back in steps of starting at 0.
5
1
2
4
He counts 0, – , – , –1 , …
5 5 5
Which of these numbers should Hassan say?
4
3
–1 –2 –3 –3 –4
5 5

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