4
Review: parts of an operation
Textbook: Part 1, lesson 4, pp. 13–15
GoalReview the names of the parts of each operation and the rules for finding an unknown part.
New words
factor · ko‘paytuvchidividend · bo‘linuvchidivisor · bo‘luvchiminuend · kamayuvchi
Explanation
Sum = addend + addend; difference = minuend − subtrahend; product = factor × factor; quotient = dividend : divisor. Unknown addend = sum − known addend. Unknown minuend = difference + subtrahend. Unknown factor = product : known factor. Unknown dividend = quotient × divisor, and unknown divisor = dividend : quotient.
Worked examples
If the product is 720 and one factor is 8, the other factor is 720 : 8 = 90.
If the dividend is 480 and the quotient is 6, the divisor is 480 : 6 = 80.
Class activity
“Find the part”: the teacher hides one part of an equation (“… + 275 = 900”); children find it and name the rule they used.
Practice
1
The sum is 9 000 and one addend is 3 275. Find the other addend.
5725
2
The difference is 1 480 and the subtrahend is 875. Find the minuend.
2355
3
The quotient is 12 and the divisor is 35. Find the dividend.
420
4
Increase the sum of 120 and 80 three times (make it 3 times as big).
600