Đang tải... (xem toàn văn)
small JUNKS or MULTIPLES of the divisor.. Divide an interger by a 2-digit divisor[r]
(1)125 ÷ 25 = 5
125 – dividend 25 – divisor
(2)Chunking is an informal method which is based on
our mental process
(3)We keep subtracting
small JUNKS or MULTIPLES of the divisor
125 ÷ 25
(4)WALT Divide an interger by a 2-digit divisor.
In order to carry out the chunking
division quickly, we need to mentally
(5)168 ÷ 14 = 14 168
28
- 28 14 x
12
12
- 140 14 x 10
Bội số 14 (Multiples of 14)
We highlight the divisor 14 in order to find the multiples of 14
(6)416 ÷ 26 = 26 416
- 260 26 x 10
156
- 130 26 x
26 16
16
We highlight the divisor 26 in order to find the multiples of 26
We circle “the times” we multiplied by 26.
- 26 26 x
(7)825 ÷ 25 = 25 825
- 500 25 x 20
325
- 250 25 x 10 75
33
33
- 50 25 x 2
25
- 25 25 x 1
(8)2912 ÷ 34 = 34 2924
- 680 34 x 20
2244
- 680 34 x 20
1564 884
- 680 34 x 20 - 680 34 x 20
204
(9)2912 ÷ 34 =
34 2924
- 3400 34 x 100
- 1700 34 x 50
÷ ÷
(10)2912 ÷ 34 = 34 2924
- 1700 34 x 50
1224
- 680 34 x 20
544
86
204
- 340 34 x 10 - 170 34 x
34 86
- 34 34 x
(11)Remember:
Should only use multiples of:
•2, 4, 5, 10, •20, 40, 50,
•100, 200,…
In order to work out the chunks quickly and to avoid careless
mistakes when subtracting