Hewlett Packard 0BII Calculator Keystrokes for the HP 0BII are shown n the tet. However, takng a mnute to revew the Quk Start secton, below, wll be very helpful n gettng started wth your calculator. Note: The Quk Start secton s also ncluded n Append C of the tet for the HP 0BII. Followng the Quk Start secton are some specfc keystrokes for usng the compound nterest formulas of Chapters 0 and. Quk Start Calculator regsters. Most keys have 2 functons. One appears n whte on the face of the key. The second functon appears n gold on the bottom half of the key. To access the second functon, press the gold shft key frst. The symbols above keys 4 through 9 (n purple) are for statstcal data. To access ths data, press the purple shft key frst. Arthmetc. Arthmetc can be done as shown below. Eample: Multply,222 by 32.8,222 [ ] 32.8 [ = ] 40,08.60 answer Notce, when keyng n,222 we dd not key n a comma (there s no comma key). The comma s shown n keystrokes for clarty and wll show up n the calculator dsplay. Also, notce that we dd not key n the decmal pont when enterng,222; the calculator presumes there s a decmal pont at the far rght. Correctng entres. If we enter a number ncorrectly, we can correct our mstake wthout havng to start the problem over agan. Pressng the backspace key [ ¹ ] gobbles up the last dgt. Pressng [ C ] clears the entre dsplayed number. Changng sgn. The sgn of a dsplayed number can be changed by pressng [+/-]. Settng the decmal. To set the decmal at, say, 8 places, press [GOLD] [DISP] 8. To change to 2 places, press [GOLD] [DISP] 2. For a floatng decmal (n whch tralng zeros are dropped), press [GOLD] [DISP] [. ]. For chan calculatons, the HP 0BII uses the nternal, more accurate number not the dsplayed number; f we want to use the dsplayed number rather than the nternal number, we round the nternal number to match the dsplayed number by pressng [GOLD] [RND].
Tme-savng regsters. Suppose we want to calculate the total monthly rent on a 72-unt apartment buldng n whch 36 unts rent for $850 each, 24 rent for $900 each, and 2 rent for $925 each. One approach would be to wrte down subtotals, then add subtotals: 36 $850 $30,600 24 $900 2,600 2 $925 +,00 Total $63,300 Here are a few approaches that can be used to save tme: use storage regsters 36 [ ] 850 [ = ] 30,600.00 frst subtotal [GOLD] [STO] 30,600.00 stored n regster 24 [ ] 900 [ = ] 2,600.00 second subtotal [GOLD] [STO] 2 2,600.00 stored n regster 2 2 [ ] 925 [ = ],00.00 thrd subtotal [ + ] [RCL] 30,600.00 frst subtotal, recalled [ = ] 4,700.00 result [ + ] [RCL] 2 2,600.00 second subtotal, recalled [ = ] 63,300.00 total use memory regsters 36 [ ] 850 [ = ] [ÿm] 30,600.00 frst subtotal, starts a new memory operaton 24 [ ] 900 [ = ] [M+] 2,600.00 second subtotal, added to memory 2 [ ] 925 [ = ] [M+],00.00 thrd subtotal, added to memory [RM] 63,300.00 total Chapters 0 & Compound nterest formulas Usng a calculator properly s essental n workng wth the compound nterest formulas of Illustraton 0-. An eample wll be gven for each of the 8 compound nterest formulas. We wll begn wth Formula A. Before startng, here are a few thngs worth notng: C There are several ways to do the arthmetc; the keystrokes shown n ths secton are only one choce. The keystrokes shown may, n some cases, be longer than another method but are used because the method s consdered to be more conceptually sound and easer to remember. C Here s a tp: Try your own keystrokes before lookng at ours. If your approach makes sense, use t because t wll be easer to remember. If you have dffculty, then revew our suggested keystrokes. C The dsplayed values shown n the keystrokes have 2 decmal places. Havng our decmal set at more or less places wll not affect the fnal answer, provded we use chan calculatons (remember that chan calculatons use the nternal, more accurate value, not the dsplayed value). Formula A Eample of Unt 0.2 You get an ncome ta refund of $,700 and depost the money n a savngs plan for 6 years, earnng 6% compounded quarterly. Fnd the endng balance usng compound nterest formulas. n 24 FV = PV ( + ) = $,700 (.05) = $2,430.5.05 [GOLD] [ y ] 24 [ = ].43.05 to the 24th power [ ],700 [ = ] 2,430.5 answer
Eample 2 of Unt 0.2 Suppose a wse man had deposted $ n a savngs account 2,000 years ago and the account earned nterest at 2% compounded annually. If the money n the account today were evenly dvded among the world s populaton, how much would each person receve, based on a world populaton of 7 bllon? n 2000 FV = PV ( + ) = $ (.02) Then dvde by 7,000,000,000..02 [GOLD] [ y ] 2,000 [ = ].59E7 account balance, n scentfc notaton [GOLD] [DISP] 9.5864733E7 balance wth more dgts, n scentfc notaton [ ] 7,000,000,000 [ = ] 22,659,247.537 amount per person [GOLD] [DISP] 2 22,659,247.54 set decmal back to 2 places (for net problem) Formula B Eample 4, Unt 0.2 You depost $00 at the end of each year for 4 years, earnng 6% compounded annually. Use compound nterest formulas to fnd the balance n 4 years. FV ' PMT ( % )n & $00 (.06)4 & = = $437.46.06.06 [GOLD] [ y ] 4 [ = ] [ - ] [ = ] 0.26 value of numerator [ ].06 [ = ] 4.37 value nsde of brackets [ ] 00 [ = ] 437.46 FV Formula 2A Eample of Unt 0.3 Your aunt says she wll gve you $2,430.5 n 6 years. Assumng that you can earn 6% compounded quarterly, what s the real value of her promse, n today s dollars? PV ' FV ( % ) ' $2,430.5 n (.05) 24 = $,700.00.05 [GOLD] [ y ] 24 [ = ].43 value of denomnator [GOLD] [STO].43 ths value s stored n regster 2,430.5 [ ] [RCL].43 recalled the value [ = ],700.00 answer
Formula 2B Eample 2 of Unt 0.3 You are sellng a valuable con. You have two offers. The frst offer s for $5,500 cash. Wth the second offer, the buyer wll pay you $2,000 at the end of each year for 3 years. Assumng that you can earn 8% compounded annually on your money, whch offer s better? PV ' PMT & ( % ) n & (.08) = $2,000 3 = $5,54.9.08.08 [GOLD] [ y ] 3 [ = ].26.08 to the thrd power [GOLD] [/] 0.79 over (.08 to the thrd power) [+/-] -0.79 changed the sgn [ + ] [ = ] 0.2 value of the numerator [ ].08 [ = ] 2.58 value nsde the brackets [ ] 2,000 [ = ] 5,54.9 answer Formula 3 Eample of Unt.4 Dale bought a rare baseball card 3 years ago for $,500. He just sold the card for $2,000 to get some money for hs college tuton. What nterest rate, compounded annually, dd Dale earn on the nvestment? ' FV PV n & $2,000 = 3 & =.00642. 0.0642% (wth 4 decmal places) $,500 2,000 [ ],500 [ = ].33 value nsde of parentheses [GOLD] [ y ] 3 [GOLD] [/] [ = ].0 prevous value to the /3 power [ - ] [ = ] 0.0 rate, n decmal form, wth decmal at 2 [GOLD] [DISP] 6 0.00642 rate, n decmal form, wth decmal at 6 [GOLD] [DISP] 2 0.0 put decmal back at 2 places Formula 4A Eample 2 of Unt. You want to accumulate $200,000 for retrement n 40 years. You can earn 6.75% compounded monthly. What amount must you depost at the end of each month n order to accumulate $200,000 n 40 years? PMT ' FV () ( % ) n & = $200,000 (.005625) = $8.7 (.005625) 480 &.005625 [GOLD] [ y ] 480 [ = ] [ - ] [ = ] 3.77 value of denomnator [GOLD] [STO] 3.77 stored the value 200,000 [ ].005625 [ = ],25.00 value of numerator [ ] [RCL] 3.77 denomnator, recalled [ = ] 8.7 answer
Formula 4B Eample 2 of Unt.2 Suppose you have accumulated $500,000, perhaps from many years of savngs or from an nhertance. You put the money n a savngs plan earnng 6% compounded monthly. You want the plan to last 40 years. How much can you wthdraw at the end of each month? PMT ' PV () & ( % ) n $500,000 (.005) = = $2,75.07 & (.005) 480.005 [GOLD] [ y ] 480 [ = ] 0.96 th.005 to the 480 power [GOLD] [/] 0.09 th over (.005 to the 480 power) [+/-] -0.09 changed the sgn [ + ] [ = ] 0.9 value of denomnator [GOLD] [STO] 0.9 stored the value 500,000 [ ].005 [ = ] 2,500.00 value of numerator [ ] [RCL] 0.9 recalled the denomnator [ = ] 2,75.07 answer
Formula 5 Eample 3 of Unt. You want to start a restaurant busness and estmate t wll take $28,000 to get started. You currently have $3,000 and can depost an addtonal $425 at the end of each month. If your savngs wll earn 9% compounded monthly, n how many months can you start your busness? For Formula 5 we must use proper sgn conventon for PV, FV, and PMT: PV = negatve $3,000 (negatve because you pay ths amount nto a savngs plan) FV = $28,000 (postve because you wll get ths amount back from the savngs plan) PMT = negatve $425 (negatve because you pay ths amount nto a savngs plan) n ' &ln PV % ( PMT ) PMT & FV ln(%) &ln &$3,000 % &$425.0075 &$425.0075 & $28,000 = = 46.83 months ln(.0075) Step : Compute and store (-$425 over.0075) 425 [+/- ] [ ].0075 [ = ] -56,666.67 value of ( - $425 over.0075) [GOLD] [STO] -56,666.67 stored n regster Step 2: Compute and store the bottom half of the numerator [ - ] 28,000 [ = ] -84,666.67 value of the bottom half of the numerator [GOLD] [STO] 2-84,666.67 stored n regster 2 Step 3: Compute and store the value of the entre numerator [RCL] -56,666.67 recall value of ( - $425 over.0075) [ - ] 3,000 [ = ] -59,666.67 value of the top half of the numerator [ ] [RCL] 2-84,666.67 recall bottom half of the numerator [ = ] 0.70 total value nsde of large brackets [GOLD] [LN] -0.35 the natural log of the prevous value [+/-] [GOLD] [STO] 3 0.35 entre numerator stored n regster 3 Step 4: Compute and store the value of the man denomnator.0075 [GOLD] [LN] 0.0 the natural log of.0075 [GOLD] [STO] 4 0.0 man denomnator stored n regster 4 Step 5: Get answer [RCL] 3 0.35 recall the value of the entre numerator [ ] [RCL] 4 0.0 recall the value of the man denomnator [ = ] 46.83 answer