Simple Interest Success Criteria Learning Intention 1. To introduce the terms Interest, Rate, pa and Deposit. 1. To be able to understand terms Interest, rate pa and Deposit 2. To show how to calculate the simple interest for 1 year 2. Can calculate Simple Interest for 1 year. 3. To show how to calculate the amount after interest is paid 3. Can calculate Simple Interest for part of a year 4. To show how to calculate the interest for part of a year

What is Interest If you DEPOSIT money in a bank account then the bank will pay you a percentage as INTEREST The RATE of interest is given as a percentage per annum per annum is another phrase for per year John DEPOSITS £200 £200 SCOTIA BANK rate of interest 3.2% p.a. Interest ( 1 yr ) = of Jill DEPOSITS £600 £600 3.2% 3.2% Interest ( 1 yr ) = of

How to Calculate Interest ( 1) The 1st step in all Simple Interest questions is to calculate the Interest due for 1 year ( annum ) Find the Interest a bank will pay on a Principal of £400 when the Interest rate is 7.5% p.a. Interest ( 1 Year ) = 7.5% of £400 of 400 400 7.5 = 7.5 ÷ 100 % x = £30

How to Calculate Interest ( 2) The 1st step in all Simple Interest questions is to calculate the Interest due for 1 year ( annum ) Find the Interest a bank will pay on a Principal of £400 when the Interest rate is 7.5% p.a. Interest ( 1 Year ) = 7.5% of £400 7.5 x 400 = 100 = 400 ÷ 100 x 7.5 = £30 7.5% is 7.5 out of 100

Calculating Interest for 1 year £730 at Rate of 2% p.a. = = (b) £290 at Rate of 4% p.a. = = (c) £1000 at Rate of 3.5% p.a. = = (d) £300 at Rate of 5% p.a. = = (e) £880 at Rate of 7% p.a. = = (f) £140 at Rate of 8% p.a. = = (g) £470 at Rate of 10.5% p.a. = = (-) √ ² C x ÷ Show Ans C 5 6 7 8 9 + - On 1 2 3 4 . = Start Next Ans

Amount in Bank after Interest Banks automatically add interest to your bank account AMOUNT = What you had in bank ( Principal ) + Interest Rate of Interest 10.5% p.a. Money in Bank £600 Interest(1 yr) = = 10.5 = 600 Amount = = 2.1 Original + Interest of (-) √ ² C x ÷ Setup 5 6 7 8 9 + - On Next 1 2 3 4 . = Ans

Amount = Principal + Interest £140 at Rate of 10.5% p.a. = = (b) £920 at Rate of 8.9% p.a. = = (c) £1050 at Rate of 3% p.a. = = (d) £720 at Rate of 7.3% p.a. = = (e) £450 at Rate of 9.5% p.a. = = (f) £800 at Rate of 4% p.a. = = (g) £560 at Rate of 1% p.a. = = Show Ans C (-) √ ² C x ÷ 5 6 7 8 9 + - On 1 2 3 4 . = Start Next Ans

Interest : Part of a year Half of the interest due for 1 year Karen deposited £2000 in her bank account in April. The bank pays a rate of 4% Interest per annum 6 months later she decided to buy a car and asked the bank teller how much interest she would get Interest for 1 year = 4% of £2000= £80 Interest for 6 month = £80 ÷ 2 = £40 Total in Bank = £2000 + £40 = £2040 6 part 4 ÷ 100 x 2000 80 Part of ….. Fraction of …. 12 total 6 12 = 6 ÷ 12 = 0.5 = a half

Part of a year 4 970 Setup Any Month of . Rate of Interest 4% months Deposit £970 for 4 = Interest(1 yr) = = As the money is left in for less than a year the Interest paid will be a fraction of that paid for 1 year part 4 Interest 4 months = x 970 Setup total Any Month = = of 6 Months (-) √ ² C x ÷ 3 Months 5 6 7 8 9 + - On 4 Months 1 2 3 4 . = Ans

Interest : Part of a Year Interest due (a) On £1320 at 7% for 6 month = = (b) On £2400 at 10.4% for 3 month = = (c) On £3600 at 3% for 4 month = = (d) On £10320 at 8% for 9 month = = (e) On £7440 at 6% for 2 month = = (f) On £4200 at 9.1% for 1 month = = (g) On £8520 at 4.5% for 8 month = = Show Ans C (-) √ ² C x ÷ 3, 4 or 6 Months 5 6 7 8 9 + - On 1 2 3 4 . = Start Next Ans

Test . . C √ ² 7 8 9 x (-) √ ² C x ÷ 4 5 6 ÷ 5 6 7 8 9 + - 1 2 3 - 1 2 (-) Ans On C √ ² 7 8 9 x (-) √ ² C x ÷ Test 4 5 6 ÷ 5 6 7 8 9 + - On 1 2 3 - 1 2 3 4 . = Ans . = +

(a) r = 16 ; s = 65 V= = (b) r = 7 ; s = 25 V= = (c) r = 18 ; s = 82 V= = (d) V= r = 10 ; s = 26 = V= (e) r = 12 ; s = 37 = (f) r = 11 ; s = 61 V= = (g) r = 13 ; s = 85 V= = Next