81
Fractions on the number ray
Textbook: Part 3, lesson 81, pp. 31–33
GoalShowing fractions on the number ray: splitting the unit segment into equal parts; coordinates of proper fractions and mixed numbers.
New words
number ray · koordinata nuriunit segment · birlik kesmacoordinate · koordinatapoint · nuqta
Explanation
To show a fraction on the number ray, split the unit segment into as many equal parts as the denominator says. The numerator tells how many parts to count. If the unit segment is split into 6 parts, the point 4 parts from 0 has coordinate 4/6. Points to the right of 1 are written as improper fractions or mixed numbers: 9 parts is 9/6 = 1 3/6.
Worked examples
The unit segment has 8 parts: point A is 5 parts from 0, so A(5/8).
The unit segment has 5 parts: point B is 2 more parts after 1, so B(1 2/5) = B(7/5).
Class activity
“Number ray game”: mark 0 and 1 on the floor and split the gap into 6 equal steps. A child steps to the fraction on the card (2/6, 5/6, 8/6).
Practice
1
The unit segment is split into 8 equal parts. Write the coordinate of the point 5 parts from 0.
5/8
2
The unit segment is split into 6 equal parts. Write the coordinate of the point 9 parts from 0 as an improper fraction and a mixed number.
9/6 = 1 3/6
3
The unit segment is split into 5 equal parts. How many parts from 0 is the point with coordinate 2 3/5?
13
4
Which point is closer to 0: the one with coordinate 3/7 or the one with 5/7?
3/7
5
The unit segment is 20 squares long. How many squares from 0 is the point with coordinate 3/5?
12