If want illustration of different answers from different calculators/devices/apps can try this:
arcsin (arccos (arctan (tan (cos (sin (9) ) ) ) ) )
*in degrees mode
http://www.rskey.org/~mwsebastian/miscprj/models.htm

This post has been edited by soonwai: Apr 11 2024, 05:43 PM

Ya wor. I haven't looked at the transactions but now I have and I see what you mean.

Looks like error on GXB part. Somehow they rounded the 3pct ie: 0.40499998461 to 0.41 (not as per their doc)
but 5pct is: 0.67499999082 to 0.67 (as per their doc)
Based on the above: 2pct = 5pct - 3pct = 0.67-0.41 = 0.26

weird...

Update:
If 3pct is calculated using (at least) 15 decimal points then it becomes 0.41. And 2pct becomes 0.26. Then it tallies with the GXB credit transactions that we see in the app for RM4941.



No change to 4941.01

This post has been edited by soonwai: Apr 11 2024, 06:26 PM

Yes, correct. Rounding means rounding up or down or no change. Yes, some cut or some add.

For RM4941, 0.67 (0.40+0.27) is correct but the 2 interest credited (0.41+0.26) is incorrect.

(0.41+0.26) is correct if 3% interest is calculated using 15 decimal points while the others are 11 decimal points (as per their example in pdf).

So far, GXBank seems consistent with rounding on the nth+1 decimal point. As stated explicitly with examples in one of their TnCs. This one is quite clear. For interest, they round to the nearest sen ie: n=2.

This post has been edited by soonwai: Apr 11 2024, 11:05 PM

Important to note that this is not a rounding mistake then it becomes clear.

Precision. 11 vs 15.

Assuming they use standard function for something as common as round. For example in php: round(number,precision);

It's observed that both 11 and 15 were used for precision.

We know they use 11 because their example uses 11.
From GXB's PDF: Interest rate per day = 3% p.a. / 365 days = 0.00008219178
(0.000082191780822)

For RM4941, if they use 11 consistently then it should 0.40 + 0.27

I believe they used 15 for the 3% because that's one way to get 0.41 + 0.26.
It may be that they use 15 or they forgot to set precision and their system defaults to 15.

It's the same reason I got 4941 which is wrong because my calculator defaults to precision of 15 decimal points. Using GXB's 11 decimal points, the magic number should 4941.01.

Rounded would be like this. Old school behaviour.
0.0445 -> 0.04
0.1247 -> 0.12
0.3449 -> 0.34
0.4550 -> 0.46

It can be more complicated. For example, in Swift, round can have different behaviours: awayFromZero, toNearestOrAwayFromZero, toNearestOrEven, towardZero, down, up or just old school round (which is toNearestOrAwayFromZero).

As far as GXB is concerned, I've tested that 0.005 rounds to 0.01. RM61 @ 3% gives 1 sen interest. (0.005000000000015) This is with at least a precision of 15 decimal points.
14 decimal points will get 0 sen. (0.00499999981)
Then you're back to 1 sen at 8 decimal points precision. (0.00500017)



The 3% is incorrect. The Raya 2% was incorrectly done because of the 3%.

This post has been edited by soonwai: Apr 12 2024, 12:27 AM

Nevermind lah. We lose 1 sen for every RM4941.00 @ 5% but GXBank lose 1 sen for every RM61 @ 3%. Just because 3% is using a precision of 15 instead of 11 decimal points.

This post has been edited by soonwai: Apr 12 2024, 12:51 AM

GX's 15 decimal points oddity has been present at least 10 days before the Raya promo. It makes them payout 1 sen for every pocket that has RM61 @3%. RM61 should be 0 sen interest if calculated with 11 decimal points.

Are you sure? I calculated 61.00. 3% and 15 decimal points.
For 11 decimal points, 61.01

just for the lulz. When dealing with bank, have no mercy, cos they won't.

Yeah, I'm sure. Less (or more) precision just affects accuracy, it doesn't make a number larger or smaller.

If no letrik, cannot charge car, how to go bank?

Ask them why the RM61 main pocket got extra 1 sen.

Yes to all. RM4941.01 in pocket.

No need RM100. Pocket RM36.61 cukup.

because you get the same amount of interest per day. 1 sen and 68 sen.

Actually not in the TnC.

This post has been edited by soonwai: Apr 19 2024, 11:00 AM

ngam ngam

Yes, Rm5k will have higher interest than RM4941. Same interest as RM4941.01.

Why, you might ask. GXBank answers "Our system uses a specific algorithm for this calculation, which might result in a slight difference (e.g., RM 0.01) compared to the figure generated by a regular calculator."


If got extra money, put in 5015.03 5014.23 into 3 pockets, that'll get you RM0.70 or extra 2 sen daily.

This post has been edited by soonwai: Apr 20 2024, 01:57 PM

Correct. Even more correct is: Max is 68 sen per pocket lah.

Note: I'm using a regular calculator app, which might result in a slight difference (e.g., RM 0.01) compared to the figure generated by a specific algorithm for this calculation.

This post has been edited by soonwai: Apr 20 2024, 01:51 PM

Also correct. Don't misunderstand. I'm not saying that you're wrong. I'm just saying for RM5015.03, I get 70 sen daily interest. If got extra pockets, I'll take a screenshot later.

Actually RM5015.03 is wrong. Later I post correct figure.

If you put RM5014.23 into 3 pockets actually can get 70 sens. 68+1+1

This post has been edited by soonwai: Apr 20 2024, 07:51 PM