Εικόνες σελίδας
PDF
Ηλεκτρ. έκδοση
[blocks in formation]

one

1. In Example No. 1, we are required to find in 1565 dollars. *

2. In Example No. 2, we are required to find of 1565 dollars.

3. In Example No. 3, we are required 4. In Example No. 4, we are required 5. In Example No. 5, we are required 6. In Example No. 6, we are required

NOTE.-Let it be observed that all the examples given on this page, indeed all division problems, may be regarded as requirements to find how many ti number of things is contained in another number of like things. Referring to Example No. 2 given above: If one were required to find one fifth of 1565 silver dollars, he might first take 5 dollars from the 1565 dollars, and put one of the dullars taken in each of five places. He might theiftake another five dollars from the number of dollars to be divided, and put one dollar with each of the dollars first taken. In this manner he would continue to distribute fives of dollars until all the dollars had been placed in the five piles. He would then count the dollars in each pile. Observe, then, that one fifth of 1565 dollars is as many dollars as $5 is contained times in $1565. It is contained 313 times; hence one fifth of 1565 dollars is 3.3 dollars

It is not deemed advisable to attempt such an explanation as the foregoing with young pupils; but the more mature and thoughtful pupils inay now learn that it is possible to solve all division problems by one thought process-finding how many times one number of things is contained in another number of like things. But if this method is adopted great care must be taken both in understanding the conditions of the problems and in the interpretation of the results obtained.

* Fill the blank with the words, how many times five dollars are contained. + Fill the blauk with the words, one fifth.

Division-Simple Numbers. 130. Find the quotient of 576 divided by 4. “Short Division."

Explanation No. 1. 4)576 One fourth of 5 hundred is 1 liundred with a remain144

der of 1 hundred; 1 hundred equals 10 tens; 10 tens

plus 7 tens are 17 tens. One fourth of 17 tens is 4 tens with a remainder of 1 ten; 1 ten equals 10 units; 10 units plus 6 units are 16 units. One fourth of 16 units is 4 units. Hence one fourth of 576 is 144.

Explanation No. 2. Four is contained in 5 hundred, 1 hundred times, with a remainder of 1 hundred; 1 hundred equals 10 tens; 10 tens and 7 tens are 17 tens. Four is contained in 17 tens, 4 tens (40) times with a remainder of 1 ten; 1 ten equals 10 units; 10 units and 6 units are 16 units. Four is contained in 16 units 4 times.

Hence 4 is contained in 576, 144 tinies.

131. Find the quotient of 8675 divided by 25. “Long Division."

Explanation No. 1. 25) 8675(347 One twenty-fifth of 86 hundred is 3 hundred, 75

with a remainder of 11 hundred; íl hundred 117

equal 110 tens. 110 tens plus 7 tens equal 117 100

tens. One twenty-fifth of 117 tens is 4 tens,

with a remainder of 17 tens; 17 tens equal 170 175

units; 170 units plus 5 units equal 175 units. 175

One twenty-fifth of 175 units is 7 units.

Hence one twenty-fifth of 8675 is 347. TO THE PUPIL.—Make another explanation of this process similar to Explanation No. 2, under Art. 130.

132. PROBLEMS. 1. 93492 ; 49

6. 5904 328 2. 92169 = 77

7. 7693 • 157 3. 72855 = 45

8. 8190 ; 546 4. 34694 38

9. 12960 = 864 5. 54875 : 25

10. 10950 438

(a) Find the sum of the ten quotients.

Division-Decimals.

133. Find the quotient of 785.6 divided by .5.

Operation

Explanation. .5)785.6'5 First place a separatrix (v) after that figure in 1571.3

the dividend that is of the same denomination as

the right hand figure of the divisor—in this case, after the figure 6. Then divide, writing the decimal point in the quotient when, in the process of division, the separatrix is reachedin this case, after the figure 1.

It was required to find how many times 5 tenths are contained in 7856 tenths. 5 tenths are contained in 7856 tenths 1571 tiines. There are yet 15 hundredths to be divided. 5 tenths are contained in 15 tenths, 3 times; in 15 hundredths, 3 tenths of a time.

Note. By holding the thought for a monient upon that part of the dividend which corresponds in denomination to the divisor, the place of the decimal point becomes apparent at once.

5 apples are contained in 7856 apples, 1571 times.
5 tenths are contained in 7856 tenths, 1571 times.

134. Solve and explain the following problems with special reference to the placing of the decimal point :

1. Divide 340 by .8
2. Divide 468.5 by .25
3. Divide 38.250 by 12.5
4. Divide 87 by 2.5
5. Divide 546 by .75
6. Divide .576 by 2.4

7. 86 ; .375
9. 75 ; .15

.8)340.00 .25) 468,50 12.5)38.250

2.5)87.04 .75)546.000

2.4).5'76 8. 94.5 +.8 10. 125.5

(a) Find the sum of the ten quotients.

Division-United States Money. 135. Divide $754.65 by $.27. Operation.

Explanation. $.27 $754.65'(2795 This means, find how many times 27 54

cents are contained in 75465 cents. 27

cents are contained in 75465 cents, 2795 214

times. 189

PROBLEM. 256

At 274 a bushel, how many bushels of

oats can be bought for $754.65 ? As 243

many bushels can be bought, as $.27 is 135

contained times in $754.65. It is con135

tained 2795 times. Therefore, 2795

bushels can be bought. 136. Divide $754.65 by 27. Operation.

Explanation. 27)$754.'65($27.'95

This means, find one 27th of $754.65. 54

One 27th of $754.65 is $27.95.

NOTE.-One might find 1 27th of 214

$754.65 by finding how many times $27 189

is contained in $754.65. See p. 52, Note. 256

PROBLEM. 243

If 27 acres of land are worth $754.65, 135

how much is one acre worth? 135

54

137. Divide $754.65 by .27. Operation.

Explanation. .27(8754 .65'($2795

This means find 100 27ths of $754.65. One 27th of $754.65 is $27.95. 100 27ths

of $754.65 is $2795. 214

NOTE.-In practice we find one 27th of 189

100 times $754. 65.
256
243

PROBLEM.

If .27 of an acre of land is worth 135

$754.65, how much is 1 acre worth at the 135

same rate ?

DENOMINATE NUMBERS.

138. Divide 46 rd. 12 ft. 8 in. by 4. Operation,

Explanation. 4)46 rd. 12 ft. 8 in. This means, find i fourth of 46 rd. 12 ft. 11 rd. 11 ft. 5 in.

8 in.

One fourth of 46 rd. is 11 rd. with a remainder* of 2 rd.; 2 rd. equal 33 ft. 33 ft. plus 12 ft. equal 45 ft.

One fourth of 45 ft. equals 11 ft.with a reinainder of 1 ft.; 1 ft. equals 12 in.; 12 in. plus 8 in. equals 20 in. One fourth of 20 in. equals 5 in. One fourth of 46 rd. 12 ft. 8 in. equals 11 rd. 11 ft. 5 in.

PROBLEM. The perimeter of a square garden is 46 rd. 12 ft. 8 in. How far across one side of it?

139. MISCELLANEOUS. Tell the meaning of each of the following, solve, explain, and state in the form of a problem the conditions that would give rise to each number process.

1. Multiply 64 rd. 14 ft. 6 in, by 8. 2. Divide 37 rd. 15 ft. 4 in. by 5. 3. Divide $675.36 by $48. 4. Divide $675.36 by 48. 5. Divide $675.36 by .48 6. Divide $675.36 by $4.8 7. Divide $675.36 by 4,8 8. Divide $675.36 by $.48 9. Multiply $356.54 by .36 10. Multiply $356.54 by 3.6 11. Multiply $356.54 by 36. 12. Multiply $275.56 by 2.25. 13. Multiply $275.56 by 27. 14. Can you multiply by a number of dollars ? 15. Can you divide by a number of dollars ?

* The word remainder in this connection suggests incomplete division. the division is complete there can be no remainder.

When

« ΠροηγούμενηΣυνέχεια »