Page 37 - 新思维数学教师用书5 试读样张

1 The number sysTem

CONTINUED

They learnt how to decompose and regroup Book. Use question 1 to make sure that learners
numbers as a basis for adding and subtracting can read, write and say numbers correctly.
numbers in columns. They used their knowledge If necessary, give learners a reference grid to
of place value to multiply and divide whole keep inside their book (see Figure 1).
numbers by 10 and 100. They rounded whole A good understanding of place value underpins
numbers to the nearest 10, 100, 1000, 10 000 and all calculation work. One of the main ideas in
100 000. place value is that the value of a digit depends
In this unit, learners build on these experiences on its position in the number; this is addressed in
as the range of numbers is increased to question 2. Try asking learners a question relating
include decimals. to real life to support this thinking: ‘Think about
Digital Classroom: Use the Unit 1 slideshow to what the digit 7 is worth in $7 and $70. You have
demonstrate examples of the number system in $67. Do you have enough money to buy a bike
everyday life. The i button will explain how to use costing $70?’
the slideshow. Learners should be able to compose, decompose
and regroup numbers, as in questions 3 and 4.
supporting learners with the Getting started Support those who struggle by using a place
exercise value chart (see Figure 2).
To support learners with work on the number Questions 5 and 6 focus on multiplication and
system, provide regular counting and other division by 10 and 100. Demonstrate on a place
number activities during lesson starters and value grid how moving a digit one place to the
ensure that there are visual representations such left represents multiplication by 10, and moving
as place value charts and number lines in the two places to the left represents multiplication by
classroom. 100. Division can be represented as movements
Check prior learning by reviewing learner’s work to the right.
using the Getting started exercise in the Learner’s

Hundred Ten
thousands thousands Thousands Hundreds Tens Ones

100000s 10000s 1000s 100s 10s 1s

Figure 1: place value reference grid

100000 200000 300000 400000 500000 600000 700000 800000 900000

10000 20000 30000 40000 50000 60000 70000 80000 90000

1000 2000 3000 4000 5000 6000 7000 8000 9000
100 200 300 400 500 600 700 800 900

10 20 30 40 50 60 70 80 90

1 2 3 4 5 6 7 8 9

Figure 2: eight hundred and five thousand, four hundred and sixty nine
805 469 = 800 000 + 5000 + 400 + 60 + 9

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