43
Practical tasks: patterns and logic
Textbook: Part 1, lesson 41, pp. 88–89
GoalLogic and fun tasks: patterns, equalities, operation signs.
New words
pattern · qonuniyatequality · tenglikoperation sign · amal belgisipuzzle · boshqotirma
Explanation
In a logic task we first look for a pattern: how do the numbers change? Three numbers can make four equalities: with 14, 13, 27 we get 14 + 13 = 27, 13 + 14 = 27, 27 − 14 = 13, 27 − 13 = 14. We try the operation signs by trial.
Worked examples
4 □ 6 □ 3 □ 2 = 5: 4 + 6 − 3 − 2 = 5.
91 − 19 = 72; 82 − 28 = 54; 73 − 37 = 36 – the difference drops by 18 each time.
Class activity
“Puzzle corner”: four stations in the room: patterns, operation signs, equalities, colouring. Groups visit each station in turn and solve one task.
Practice
1
64 − 46 = ? (continue the pattern)
18
2
45 + 12 □ 66 − 11 (>, <, =)
>
3
91 − 44 − 27 = ?
20
4
A shop has 60 devices: 21 tablets, 24 laptops and the rest printers. How many printers?
15