Page 10 - 新思维数学学生用书4 样章

1 Numbers and the number system

This unit is all about our number system. You will look at linear sequences

and non-linear sequences, negative numbers, multiplying and dividing by

10 and 100, and place value.

Imagine you save $2 each week. $

Can you write a number sequence for how much you

have at the end of each week?
You add the same amount each time, so this is

$
$
a linear sequence. $ $ $ $
$
$
The term-to-term rule is ‘add 2’. $ $ $

If you save a different amount each time, the sequence will be non-linear.

One of the main ideas in place value is that the value of a digit depends on

its position in the number.

Think about what the digit 7 is worth in $7 and $70.

Do you have enough money to buy the bike?

There are $7 in the bag. The bike costs $70.

Think about the numbers 126 and 162.

What is the value of the digit 2 in each number?

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