EXERCISE K.

Find the cost of a dozen things at 21d. each.

Find the cost of a dozen things at 2s. 34d. each. 28. = 24d. ; 2s. 3d. = 27d.; 2s. 3 d. = 27 d., therefore a dozen will cost 27 shillings £1. 78. 6d. =

Find the cost of a dozen things at 3s. 81d. each. 3s. = 36d.;

=

38. 8d. 44d.; 38. 81d. 441d., therefore a dozen things will cost =

441 shillings £2. 48. 3d.

=

=

Find the cost of a dozen things at 7s. 1ąd. each. 7s. 1d. = 85d.; 7s. 1ąd. cost 85 shillings = £4. 58. 9d.

7s. = 84d.; 852d., therefore a dozen things will

EXERCISE L.

8. d.

Find the cost of a dozen things at 2 7 each.

دو

9101

3

If a dozen things cost 1s., each thing will cost 1d.; if 6d., d.;

if 3d., d.; and if 9d., 3d.

Ans. 9d.

Find the cost of one thing at 9s. a dozen. Find the cost of one thing at £1 a dozen. Ans. 1s. 8d., because £1= 20s., therefore each article will cost 20d., and 20d. = 1s. 8d. Find the cost of one article at 8s. 6d. a dozen. Ans. 8d., because 8s. 6d. is eight and a half shillings, therefore each article costs eight and a half pence.

Find the cost of one article at 15s. 9d. per dozen. Ans. 1s. 3§d., because 15s. 9d. is fifteen and three-quarter shillings, therefore each article will cost fifteen and three-quarter pence.

Find the cost of one article at £1. 1s. 3d. a dozen. Ans. 1s. 91d., because £1. 18. 3d. is twenty-one and a quarter shillings, therefore each article will cost twenty-one and a quarter pence, or 1s. 91d.

These six cases are intended to give the pupil facility in interconverting pounds, shillings, and pence. Other applications of the shillings and pence tables may be found equally serviceable, as, for instance, the calculation of interest at 5 per cent. per annum, which amounts to a payment of a shilling per pound each year, and a penny per pound each month.

Case I. Find the interest to be paid on a loan of £45 for one month. Ans. 38. 9d., because for one pound we pay one penny, therefore for £45 we pay 45 pence, or 3s. 9d.

Case II. Find the interest to be paid on a loan of £56 for one year. Ans. £2. 16s., because for one pound we pay one shilling, therefore for £56 we pay 56 shillings, or £2. 16s.

EXERCISE P.

How many shillings are 14 pence? Ans. 1

S. d.

629

2 8

How many pounds are 91 shillings? Ans. 4 11

0

CHAPTER III.

ADDITION.

1. CONCRETE. The word Addition is derived from the Latin addo, and means putting together.

2. Learn by heart: This sign (+) is called PLUS, and means that the quantities between which it stands are to be added together.

3. Learn by heart: In Addition, the quantities to be added together are called the ADDENDA, and the answer is called the SUM.

Ans. £24.

4. Add together £5, £4, £8, £7.
Find the sum of 6s., 5s., 9s., 4s., 7s.
Simplify 7d. + 4d. + 9d. + 6d. +11d.

Ans. 31s., or £1. 11s.
Ans. 37 pence, or 3s. 1d.
Add together 8s. 3d. and 7s. 4d. Ans. 15s. 7d.

Add together 48. 9d., 58. 4d., 6s. 7d., 98. 3d., and 28. 8d. It is usual and convenient to write the addenda under one another, thus:

Let us begin with the shillings, as the more important. Ans. 26 shillings and 31 pence; but as 31 pence are 2s. 7d., the handier answer is 28s. 7d., or £1. 8s. 7d. From this it will be seen that labour would be saved by beginning with the pence, as the sum of the shillings can make no alteration in that of the pence, while the sum of the pence may yield some shillings.

Simplify 6s. 8d. + 4s. 3d. + 5s. 9d. + 3s. 11d. + 9s. 10d. + 1s. 2d.

Add up the pence column, 43 pence, which are 3s. 7d. ; put down the 7d. under the pence, and add on or carry the 3s. to the shillings'