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Practice and test work

Lessons 11–12 · 2 lessons · N. I. Taylaqov (general editor), A. B. Akhmedov, M. D. Pardayeva, A. A. Abdug‘aniyev, U. M. Mirsanov. Informatics and Information Technologies, Grade 10, 1st edition. “Extremum-Press”, Tashkent, 2017
11

Practical lesson for consolidation

Textbook: pp. 28–29
GoalCombines formulas, references, functions and IF in one practical task and checks the result.
New words
template table: a prepared layout whose numbers can be changed · andoza jadvaltotal row: the row that adds up a column · yakuniy qatormean: the sum of the values divided by their number · o‘rtacha qiymatsanity check: estimating the answer roughly to see if it is reasonable · natijani tekshirish
Explanation

In a practical lesson a table is built from scratch and all the tools of the earlier lessons are used together. The order of work: first the headings and the starting data are written; a shared number such as a tax rate is put in a separate cell and joined with an absolute reference; then the formula for one row is written and copied down; at the end a total row is added. Always check the result with a rough estimate: 12% VAT should be a little more than a tenth of the price. Save the file with a meaningful name (for example prices_VAT.xlsx) and keep a copy in another place as well. When working on another person’s or a shared file, make a copy before changing its formulas.

Worked examples
Task 1. Prices are in B2:B4: 250 000, 90 000, 140 000 so‘m; the 12% VAT rate is in E1. C2 = B2*$E$1 (30 000; 10 800; 16 800), D2 = B2+C2 (280 000; 100 800; 156 800), D5 = SUM(D2:D4) = 537 600. Check: the total price is about 1.12 times 480 000 ≈ 537 600.
Task 2. Three test marks are in B2:D2: 68, 74, 80. E2 = (B2+C2+D2)/3 = 74. F2 = IF(E2>=70,"yaxshi","oddiy") gives “yaxshi”. When the formulas are copied to other students’ rows, each one processes its own marks.
Class activity

“Mini-shop”: groups build a table of 5 invented products, prices and VAT, then change one price in another group’s file and predict in advance how the total will change.

Practice
1
How many so‘m is 12% VAT on a product costing 140 000 so‘m?
2
Prices with VAT are 280 000, 100 800 and 156 800 so‘m. What is the total in so‘m?
3
If the marks are 68, 74 and 80, what is the mean?
4
Why do we check the result with a rough estimate?