Page 11 - 新思维数学学生用书4 样章
P. 11
1 Numbers and the number system
1.1 Counting and sequences
We are going to ...
• count on and back in steps of tens, hundreds and thousands starting
from any number
• count back through zero to include negative numbers such as −2
• recognise linear sequences and non-linear sequences
• extend sequences and describe the term-to-term rule
• recognise and extend patterns that represent square numbers.
You will continue counting forwards and
backwards in steps of constant size and you
will start to use negative numbers.
Around the coasts of Antarctica temperatures
are between −10 °C and −30 °C.
Try counting back in tens
starting at 30 and ending difference sequence
with −30.
linear sequence spatial pattern
negative number square number
Worked example 1 non-linear sequence term
Carlos writes a number rule term-to-term rule
sequence.
The first term in his sequence is 8.
He uses the rule ‘subtract 2’ to work out the next term.
What is the fifth term in his sequence?
Start with 8 and subtract 2 each time
−2 −2 −2 −2
8 6 4 2 0 until you have five terms.
Answer: The fifth term is 0.
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