9
Review: number ray and coordinate grid
Textbook: Part 1, lesson 9, pp. 28–30
GoalReview the number ray, scales and the coordinate grid: locating a point.
New words
number ray · koordinata nuriorigin (starting point) · hisob boshiunit segment · birlik kesmacoordinate grid · koordinata burchagi
Explanation
A number ray has an origin, a direction and a unit segment. To find the value of one division, divide the difference between two marked numbers by the number of divisions between them. Two perpendicular rays make a coordinate grid. A point is written A(3; 5): first 3 steps along the horizontal ray, then 5 steps up.
Worked examples
There are 4 divisions between 0 and 24, so one division is 24 : 4 = 6. The marks are 0, 6, 12, 18, 24.
To find B(4; 2) go 4 squares right and 2 squares up.
Class activity
“Battleship”: partners draw a coordinate grid on squared paper; one says the coordinates of a point and the other marks it.
Practice
1
On a ray there are 5 divisions between 0 and 60. What is the value of one division?
12
2
On a ray where one division is 8, which number is at the 5th mark from the origin?
40
3
The points A(1; 2) and B(5; 2) lie on one horizontal line. How many units long is AB?
4
4
If A(1; 2), B(5; 2), C(5; 6), D(1; 6) are joined in order, what shape appears?
A square (side 4 units)