51
Dividing round numbers
Textbook: Part 2, lesson 51, pp. 37–39
GoalDividing round numbers: remove the same number of zeros from the dividend and the divisor.
New words
round number · yaxlit sonstrike out zeros · nolni olib tashlashdivisor · bo‘luvchidividend · bo‘linuvchi
Explanation
To divide round numbers, strike out as many zeros from the right of the dividend as the divisor has. 6 300 : 900 = 63 : 9 = 7. If zeros remain in the dividend, they go to the quotient: 72 000 : 600 = 720 : 6 = 120.
Worked examples
4 800 : 400 = 48 : 4 = 12.
420 000 : 60 = 42 000 : 6 = 7 000.
Class activity
“Rub out the zeros”: an example is written on the board; children take turns rubbing out the same number of zeros and solving the shorter example.
Practice
1
8 400 : 70 = ?
120
2
45 000 : 900 = ?
50
3
540 000 : 600 = ?
900
4
480 bags of cement were delivered to a building site. A crane lifts 40 bags at a time. How many lifts does it make?
12
5
A truck uses 200 l of fuel a day. For how many days will 6 000 l last?
30