Dawnbridge

Casio fx-CG50 field manual for IB Math

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7

Calculating logarithms

All courses

Evaluate log10​x, lnx, and logb​x in any base for positive arguments.

Goal

Compute ​log10​(123),  ​ln(123), and ​log2​(50).

1

Base 10: from the MAIN MENU, open Run-Matrix (icon 1). Press , type the argument with , and press . No closing parenthesis is needed.

2

Natural log: press , type , and press .

3

Any other base: press (MATH), then (logab) to insert the log▯(▯) template: the cursor starts in the base box. Type the base with , press to hop into the argument box, type , and press .

Result

​log10​(123)≈2.09,  ​ln(123)≈4.81, and ​log2​(50)≈5.64.

MathRadNorm2
d/cReal
log(123)
2.089905111
ln(123)
4.812184355
log2​(50)
5.643856190
JUMPDELETE▶MAT/VCTMATH

Your turn

Work each one on your calculator, then check the answer.

  1. 1

    Compute ​log10​(47),  ​ln(30), and ​log2​(90).

  2. 2

    Compute ​log10​(0.35),  ​ln(0.5), and ​log5​(3).

  3. 3

    Compute ​log10​(2024),  ​ln(250), and ​log3​(200).