THE SEQUENCE OF OPERATIONS. CALCULATION OF THE VALUE OF AN EQUATION.


1.      Why do you get different answers if you calculate with same numbers?

120 + 40 · 2 = ..........
(120 + 40) · 2 = .......... 

90 + 60 : 5 = ..........
(90 + 60) : 5 = .......... 
100 - 30 · 2 = ..........
(100 - 30) · 2 = .......... 

500 - 180 : 2 = ..........
(500 - 180) : 2 = ..........


2.
The value of which equations does not change without using parentheses? Why

(50 · 4) + (60 · 3) = ..........
(300 : 6) - (280 : 7) = .......... 
(300 - 50) · 6 = ..........
(320 + 120) : 4 = ..........
10 · (40 + 10) : 5 = ..........
750 - (80 + 5 · 6) = .......... 


3.
Do your sums! Check if the answer is amount these numbers beside.

186 + 4 · 15 - 90 = ..........
579 - 3 · 30 + 10 · 0 = ..........
463 + 12 · 5 - 4 · 10 = ...........
156, 166, 146
499, 489, 479
483, 493, 473