Two years ago I posted an article talking about the issues of mainstream calculators (fx-50FHII and fx-3650PII) used by HK students. At that time I didn't have an fx-3650PII on hand as fx-50FHII was (and is) a superior model in HK. Today, I have to buy it as there will be some upcoming tests for definite integral and my fx-50FHII doesn't have it. Therefore, it's time for the review of this calculator and comparison to my 3-year-old fx-50FHII

Unboxing

Package (Front)


Package (Back)


Content: fx-3650PII, Chinese/English User's Guides


I bought fx-3650PII at the price of HK$248 in The Commercial Press (商務印書館), though I redeemed it using $250 worth book vouchers Before the pandemic, it was sold at around HK$200 and $175 at my school in 2019. Although it's reasonable to raise the price because of shortage of chips, the price of fx-50FHII as of now is $268 which is just $20 more expensive but with more general features.

The package design and content of this calculator are very similar with those of fx-50FHII. From the package, it clearly shows this calculator has 390 bytes for programming, which is smaller than 680 bytes found in fx-50FHII. Also, fx-3650PII has a mix of both dot-matrix and segment displays as seen in the package, again the same as fx-50FHII.

At a glance

Covered


Back


Front (Left: fx-3650PII, Right: fx-50FHII)


fx-3650PII has exactly the same key layout and almost has the same functions as fx-50FHII, with the exceptions of [Prog] being grey instead of orange, [FMLA] being replaced by [∫dx] (thus missing 23 maths formulas) and missing of 40 scientific constants (Shift + 7). This means fx-3650PII is for HK students who rely on calculus calculation.

Since the texture of this calculator is exactly the same as fx-50FHII, I will say both of them have a metalic coating and bouncy keys when they unboxed for the first time, but after a year or two, they start wearing out and become a heavy-duty plastic. However, this is still better than my fx-9750GIII where it just started out as a plastic

For now it seems like both calculators have not too much differences compared to each other, right? Well, the next section is an another story.

Criticism 1: Extremely poor display

This is what the display looks like when you turn on this calculator for the first time:


Even worse, when you adjust the viewing angle, the whole screen is completely blackened:


That is just under the normal contrast. When I set it to the lowest possible:



This time the display gets a bit better, but as a result, the texts become lighter and barely readable when directly looking at the display. Compared to fx-50FHII:

Darkest contrast



Lightest contrast


fx-50FHII has a way more consistent display at any viewing angles. This fact single-handedly proves that fx-50FHII is just superior. I don't know why fx-3650PII has such a bad display quality.

Criticism 2: Even fewer programming bytes

390 bytes for programming... and still 4 program slots And the program editor is completely linear. Moreover, when you create a new program, you have to choose one of 5 modes (COMP, CPLX, BASE, SD, REG). That means you cannot use the complex functions or stat commands in COMP mode. Besides, Casio Basic in this calculator is absolutely lackluster. Why? It has no Locate, Getkey functions etc, no nest feature (you cannot do double nests in other words), only 7 letter variables with no list variables... Certainly, this calculator is not suitable for storing complex programs.

Criticism 3: Very slow calculus operations

Calculus in fx-3650PII is super slow. Sometimes, it can take several tens of seconds to calculate some of the integrals. This wastes your precious exam time if you don't properly practice time management, especially in HKDSE where the maximum efficiency is the crucial point to achieve higher levels.

Conclusion
If you are an HK student, do not buy fx-3650PII unless you attend calculus electives. It's such a pity that students who choose M2 as one of their electives need to pay for the similar price just for single usage. Casio, if you do not want to add any new features in the next generation of HKEAA-approved calculators, at least combine them into one as splitting both only creates economic pressures to some families with M2 student. A total price of both calculators, which is HK$516, could buy an fx-5800P which has far more features and larger programming bytes.