Scientific Calculator

DEG

Scientific Calculator for Class, Lab, and Homework

Work through trig, powers, roots, and logarithms in one place. This scientific calculator takes a whole problem at once, works it out in the right order, and keeps the last answer ready for your next step. The calculator runs in your browser, with nothing to install.

Homework, problem 4

A 12 ft ladder leans on a wall.

Its foot is 3 ft from the wall.

How high up does it reach,

and at what angle?

h = √(12² − 3²)

Answer

11.62 ft

at 75.52°

What You Can Do with an Online Scientific Calculator

Ladder problem

√(12² − 3²): 11.619
cos⁻¹(3 ÷ 12): 75.522
12 × sin(Ans): 11.619

DEG mode

Enter the Problem as Written

Enter the whole problem, then press equals. The calculator works out powers and roots first, then multiplication and division, then addition and subtraction, the order you learned in math class. Add parentheses around any part you want done first. You can leave out the × in front of π or an opening parenthesis, as in 2π, and it still multiplies. On a computer, the keyboard works too: digits, + − * /, ^, ( ), Enter for equals, Backspace, and Esc to clear.

Ladder against a wall

Work in Degrees or Radians

The calculator starts in degrees, and the badge at the top of the display shows DEG or RAD. Tap DEG/RAD to change it. The mode sets how sin, cos, and tan read the angle you enter, and which unit sin⁻¹, cos⁻¹, and tan⁻¹ answer in. If sin(90) shows about 0.894 instead of 1, you're in radians. A problem with a degree sign wants degrees, and one written with π, like π/3, usually means radians.

With 2nd on

sin: sin⁻¹
cos: cos⁻¹
tan: tan⁻¹
√: ∛
n!: 1/x
log: 10ˣ
ln: eˣ

Find Angles and Roots with 2nd

Tap 2nd and seven keys take on a second job: sin, cos, and tan turn into sin⁻¹, cos⁻¹, and tan⁻¹, √ into ∛, n! into 1/x, log into 10ˣ, and ln into eˣ. A 2nd badge appears on the display, and the keys stay switched until you tap 2nd again. The inverse trig keys get an angle back from a ratio, such as a ladder's angle from its length and how far its foot sits from the wall.

Work Through the Ladder Problem Key by Key

Here's the ladder from the pictures, solved on this calculator: 12 feet long, with its foot 3 feet from the wall. Each step lists the keys to press. After that come a few keys worth knowing.

Example: A 12-Foot Ladder's Height and Angle

Check the angle mode
Look for DEG at the top of the display. If it says RAD, tap DEG/RAD once.
Find the height
Press √, 12, x², −, 3, x², ), then =. The display shows 11.6189500386, so the ladder reaches about 11.62 feet up the wall.
Find the angle
Press 2nd, cos⁻¹, 3, ÷, 12, ), then =. You get 75.5224878141, or about 75.52° between the ladder and the ground.
Check it with Ans
Press 2nd again to switch it off, then 12, ×, sin, Ans, ), and =. Ans holds the angle from the last step with every digit, so the height comes back as 11.6189500386.

Keys Worth Knowing

Ans: The last answer, kept with every digit even when the screen shows fewer. Press a key such as + or x² right after = and the answer carries on by itself.
M+, MR, and MC: M+ adds the current answer to memory, MR puts the stored number into your problem, and MC clears it. An M on the display means memory holds a number.
π: Pi, about 3.14159: the distance around a circle divided by the distance across it.
e: About 2.71828, the base of the natural logarithm, ln. With 2nd on, ln turns into eˣ.
n!: Factorial: a whole number times every whole number below it, down to 1, so 5! is 120. 0! is 1.
⌫ and AC: While you type, ⌫ removes the last key you pressed, so a whole sin( goes at once. AC clears the problem, but Ans and memory stay.

Scientific Calculator FAQs

What is the difference between log and ln?

They're logarithms with different bases. The log key works in base 10, the common logarithm, so log(1000) is 3. The ln key gives the natural logarithm (opens in a new tab), which uses base e, so ln(e) is 1. With 2nd on, they turn into 10ˣ and eˣ, which undo them.

How do I enter a number like 6.02 × 10²³?

Use the EXP key, which means times ten to the power of. For 6.02 × 10²³, press 6.02, EXP, then 23, and for a tiny number such as 4.5 × 10⁻⁴, press − right after EXP. Answers of a trillion or more, or closer to zero than a billionth, come back with an e in them: 6.02e23 means 6.02 × 10²³.

Why does the calculator show Error?

Error means the problem has no answer the calculator can show, or it can't be read. Common causes are dividing by zero, the square root or log of a negative number, tan(90) in degree mode, and empty parentheses. Type the problem again with the fix, or press AC first. Ans and memory stay as they were.

Can I work with fractions?

There's no fraction key, so type a fraction as a division: ¾ is 3 ÷ 4. When the top or bottom holds a sum, put it in parentheses, like (1 + 2) ÷ (3 + 4). Answers come out as decimals. For a percent of a number or a percent change, the percentage calculator gets there with less typing.

What is the difference between a scientific and a graphing calculator?

A scientific calculator works out one answer at a time, with keys for trig, logs, powers, and roots. A graphing calculator does all of that, draws graphs and tables of values too, and many can run programs. This one doesn't draw graphs, so for a plot you'll need a graphing tool.

How accurate are the answers?

The screen rounds answers to at most 10 decimal places, and Ans and memory keep the full value behind them. Computer math can leave tiny rounding leftovers, and the calculator cleans up the common ones, so 1 − 0.9 − 0.1 gives 0 and sin(180) in degrees gives 0.

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Solve Your Next Problem with the Scientific Calculator

Homework, a lab write-up, or a quick measurement to check? Scroll back up, enter the problem, and read the answer. Like every free calculator on EZ Calculator, it's ready to use with nothing to sign up for.