This one does not. Tap anywhere in the expression, move the cursor, and change the digit you got wrong. The portrait keypad covers what most days need — the four operations, percentages, parentheses, a sign toggle — with a running preview showing the answer as you type, so you can see where a long expression is heading before you press equals. Turn the phone sideways and you get a full scientific pad across two pages.

Here are just a few of the great features of Scientific Calculator:

• An editable display: tap into the expression, move the cursor and correct a single digit, instead of clearing everything and retyping it.
• A running preview: the answer updates as you type, so a mistake in a long expression shows up before you commit to it.
• A full scientific keypad: in landscape: roots, absolute value, natural log and log base 10, sine, cosine and tangent with their inverses, the hyperbolic functions, powers, factorial, e to the x, pi and e, and a degrees/radians switch.
• History you can search: recent calculations are kept on the device and searchable by expression or by result. Tap one to bring its answer back, copy it, or swipe it away.
• Seven tools built in: unit converter (length, weight, volume, area, temperature), tip calculator with bill splitting, discount and markup, percentage change, BMI, date difference and GPA.
• Made to live on your phone: light, dark or system themes, six accent colours and a custom picker, and optional haptic feedback on every key.

A calculator that lets you fix your mistakes. Download Scientific Calculator: History and stop retyping.