Lessons 3–4 · 2 lessons · K. T. Suyarov, Z. B. Sangirova, M. T. Umaraliyeva, S. G‘. Xasanova, M. K. Yuldasheva, D. T. Hasanova. Natural Science, Grade 6 (new edition). Republican Education Centre, 2022
3
Practical: Showing data on a graph
Textbook, pp. 11–12
GoalCalculate an average, draw a graph from a table of data and draw a conclusion from the graph.
New words
average (mean) · o‘rtacha qiymattable · jadvalgraph · grafikaxes (the horizontal and vertical lines of a graph) · koordinata o‘qlari
Explanation
To find the average of several quantities we add them all and divide the sum by how many there are. For example, if three books have masses 600 g, 400 g and 500 g, the average mass is (600 + 400 + 500) : 3 = 500 g. We first write measurements in a table and then draw a graph. On the horizontal axis we put what we observe (for example the hour or the group name), on the vertical axis the measured quantity (for example height or temperature), and mark every value with a point. A graph shows change (rise, fall, the highest point) faster than a row of numbers. Each axis must show its unit (cm, °C) and clear divisions.
Worked examples
Four pupils are 145 cm, 147 cm, 146 cm and 150 cm tall. Average height: (145 + 147 + 146 + 150) : 4 = 588 : 4 = 147 cm.
Let the temperature at 8, 10, 12, 14, 16 and 18 o’clock be 18, 24, 30, 32, 28 and 24 °C. On the graph the points rise first, reach the highest value (32 °C) at 14:00, then fall. Average temperature: 156 : 6 = 26 °C.
Class activity
Practical work: divide the class into four groups by birth month (Jan–Mar, Apr–Jun, Jul–Sep, Oct–Dec). Each group measures heights with a tape, records them in a table and calculates the average height. Then draw a graph with group names on the horizontal axis and average height on the vertical axis. Safety: measure standing against a wall, in flat shoes or none, without pushing each other.
Practice
1
Three numbers: 12, 15 and 21. Find their average.
16
2
Rainfall over five days was 2, 0, 4, 6 and 3 mm. What is the average in mm?
3
3
What is written on the horizontal and vertical axes of a graph?
Horizontal axis: what we observe (time, group); vertical axis: the measured quantity (temperature, height).
4
Why do we show results on a graph and not only in a table?
A graph shows change (rise, fall, the largest value) at a glance, which makes comparing easier.