Page 25 - 新思维数学学生用书6 样章

2 Numbers and sequences

9 Samira counts on from 20 in steps of 1.001:
20, 21.001, 22.002, 23.003, …

Write the first number Samira says which is bigger than 30.

Think back over the work you have done on sequences.

What have you learned?
Is there anything you need to get better at?

Think like a mathematician

The diagram shows the 3rd hexagonal number: 15

first five hexagonal 2nd hexagonal number: 6
numbers: 1st hexagonal number: 1

1, 6, 15, 28, 45, …

How does the sequence
continue? What is the

next number in the sequence?

Write these numbers as the sum of two
hexagonal numbers: 12, 21, 29, 30. Count the dots inside and on

The first one is done for you. the perimeter of each hexagon

12 = 6 + 6
Investigate which other numbers, less than 100, can be written as the sum of two

hexagonal numbers.
You will show you are specialising when you investigate which other numbers, less

than 100, can be written as the sum of two hexagonal numbers.

Look what I can do!

I can count on and back using fractions and decimals.

I can find and use the position-to-term rule in a sequence.

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