103
Simple equations
Textbook: Part 3, lesson 103, pp. 107–108
GoalSimple equations: finding the unknown component, the root, checking.
New words
root · ildizunknown · noma’lumchecking · tekshirishcomponent · komponent
Explanation
A simple equation has one operation on the left. To find the unknown we recall the parts of operations. Unknown addend = sum − known addend. Unknown minuend = difference + subtrahend. Unknown subtrahend = minuend − difference. Unknown factor = product : known factor. Unknown dividend = quotient × divisor. Unknown divisor = dividend : quotient. A number that turns the equation into a true equality is its root. To check, substitute the root and calculate.
Worked examples
x + 300 = 900 → x = 900 − 300 = 600. Check: 600 + 300 = 900.
48 : t = 6 → t = 48 : 6 = 8. Check: 48 : 8 = 6. z − 180 = 320 → z = 320 + 180 = 500.
Class activity
“Equation chain”: each child writes an equation, the neighbour solves it, checks the root and passes a new equation along.
Practice
1
Solve the equation x + 14 205 = 50 000.
35795
2
Solve the equation 720 − y = 340.
380
3
Solve the equation z − 180 = 320.
500
4
Solve the equation 48 : t = 6.
8
5
60 singers took part in a show: 24 men and x women. Find x with an equation.
36