60 Chapter 1 Whole Numbers
Change the from 4 to 3 in the tens column of the quotient.
3 and 23, and their product, 69, from 83, to get 14.
the 2 from the ones column of the dividend.
Ask: “How many times will 23 divide 142?” We can the answer to
that question by thinking is 7, and we write the 7 in the ones column
of the quotient. 7 and 23, and write their product, 161, under 142.
Because 161 is greater than 142, the estimate of 7 for the ones column of
the quotient is too large.We will erase the 7 and decrease the estimate of
the quotient by 1 and try again.
Change the from 7 to 6 in the ones column of the quotient.
6 and 23, and their product, 138, from 142, to get 4.
The remainder
The quotient is 36, and the remainder is 4. We can write this result as 36 R 4.
To check the result, we multiply the divisor by the quotient and then add the
remainder. The result should be the dividend.
Check: Quotient Divisor Remainder
Dividend
Since 832 is the dividend, the answer 36 R 4 is correct.
832
(36 23) 4 828 4
Multiply subtract
estimate
36
23 832
69
142
138
4
Multiply
14 2
estimate
37
(^23) 832
69
142
161
Bring down
3
(^23) 832
69
142
Multiply subtract
estimate
3
23 832
69
14
EXAMPLE 5
Divide:
StrategyWe will write the problem in long-division form and follow a four-step
process:estimate, multiply, subtract,and bring down.
WHYThis is how long division is performed.
Solution
We write the division in the form: Since 518 will not divide 1, nor 13,
nor 130, we divide 1,301 by 518.
Ask: “How many times will 518 divide 1,301?” Since 518 is about 500,
we can the answer to that question by thinking is
about 2, and we write the 2 in the tens column of the quotient.
2 and 518, and their product, 1,036, from 1,301, to
get 265.
Multiply subtract
estimate 13 5
2
518 13011
1036
265
(^518) 13011.
13,011
518
Self Check 5
Divide:
Now TryProblem 43
28,992
629