Page 12 - 新思维数学学生用书4 样章
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1.1 Counting and sequences
Worked example 2
The numbers in this sequence increase by 50 each time.
60 +50 110 +50 160 +50 ...
What is the first number greater than 1000 that is in the sequence?
Explain how you know.
60, 110, 160, 210, 260, ... Write down the first few terms.
(You could write down all the terms in the
sequence, but it would take a long time.)
Answer: The terms all end in 10 or 60
so the first number greater than 1000 is 1010.
Exercise 1.1
1 a Mia counts on in steps of 100.
She starts at 946.
Write the next number she says.
b Kofi counts back in steps of 100.
He starts at 1048.
Write the next number he says.
c Bibi counts on in steps of 1000.
She starts at 1989.
Write the next number she says.
d Pierre counts back in steps of 1000.
He starts at 9999.
Write the next number he says.
e Tara counts back in ones.
She counts 3, 2, 1, 0.
Write the next number she says.
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