0912 p11-p13 比例式的計算

動動腦，想一想

​2 X □ = ​3 X □

動動腦，想一想

​2 X □ = ​3 X □

​2

​3

動動腦，想一想

​2 X □ = ​3 X □

​2

​3

​還有沒有其他可能？

動動腦，想一想

​2 X □ = ​3 X □

​4

​6

動動腦，想一想

​2 X □ = ​3 X □

​4

​6

​還有沒有其他可能？

動動腦，想一想

​2 X □ = ​3 X □

​？

​12

動動腦，想一想

​2 X □ = ​3 X □

​？

​12

Fill in the Blanks

2 X 12 = ​3 X □

□ =？

動動腦，想一想

​2 X a = ​3 X b

​3
​6
​9
​12

​2
​4
6
8

動動腦，想一想

​2 X a = ​3 X b

​3
​6
​9
​12

​2
​4
6
8

​：
​：
：
：

動動腦，想一想

​2 X a = ​3 X b

​3
​6
​9
​12

​2
​4
6
8

​：
​：
：
：

​a：b = 3：2

Fill in the Blanks

2 a = ​3 b

a：b =？

Fill in the Blanks

5 a = ​3 b

a：b =？

動動腦，想一想

​2 X a = ​3 X b = 5 X c

動動腦，想一想

​2 X □ = ​3 X □ = 5 X □

動動腦，想一想

​2 X □ = ​3 X □ = 5 X □

​3X5

​2X5

​2X3

Drag and Drop

2 X ​

Placeholder

= 3 X ​

Placeholder

= 5 X ​

Placeholder

Drag these tiles and drop them in the correct blank above

3 X 5

2 X 5

2 X 3

Drag and Drop

2 X a ​ = 3 X b​ = 5 X c​

2 X ​

Placeholder

= 3 X ​

Placeholder

= 5 X ​

Placeholder

Drag these tiles and drop them in the correct blank above

3 X 5

2 X 5

2 X 3

Drag and Drop

2 X a ​ = 3 X b​ = 5 X c​

2 X ​

Placeholder

= 3 X ​

Placeholder

= 5 X ​

Placeholder

Drag these tiles and drop them in the correct blank above

15

10

6

Drag and Drop

2 X a = 3 X b​ = 5 X c​



a：b：c =

Placeholder

：

Placeholder

：

Placeholder

Drag these tiles and drop them in the correct blank above

15

10

6

​比例式的運算

Multiple Choice

a : b : c = 1 : 2 : 3

下列何者正確？

• a = 1

• b = 2

• c = 3

• c = a + b

a:b:c=1:2:3

a不一定是1
b不一定是2
c不一定是3

a:b:c=1:2:3

但是我們可以假設
a是1 => a = 1
b是2 => b = 2
c是3 => c = 3

Fill in the Blanks

若 a : b : c = 1 : 2 : 3

則 5a：2b：3c =？

Fill in the Blanks

若 a : b : c = 3 : 4 : 1

則 (a+b)：(b-c)：2a =？