How to Use Think Mode for Hard Problems in Grok

Switch Grok into its slower reasoning mode for math, logic, and multi-step problems where the default fast answer falls short.

6 minIntermediate

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Grok has a Think mode that makes the model reason step by step before answering, trading speed for accuracy. It is the right tool for math, logic puzzles, code debugging, and anything with multiple dependent steps. This guide shows when to turn it on and how to prompt so the extra thinking is actually used well.

What you need

Access to Grok on X or grok.com
A problem that has a verifiable correct answer
Patience for a slower response

Step 1: Turn on Think mode

Below the prompt box, Grok shows a Think toggle alongside the regular send option. Enable it before sending a hard question. In Think mode Grok works through the problem internally and you will see it take noticeably longer.

Grok - mode toggle

[ Ask Grok... ]

( ) Auto ( ) Fast (x) Think

Think reasons step by step. Slower, more accurate.

The Think option next to the prompt box.

Step 2: State the problem cleanly with constraints

Think mode rewards a precise problem statement. Spell out the goal, the inputs, and any constraints, and ask Grok to show its reasoning and state assumptions. Vague questions waste the extra compute on guessing what you meant.

prompt

A train leaves at 9:00 going 60 mph. A second leaves the same station at 9:40 going 80 mph, same direction.
At what time does the second catch the first? Show each step and state any assumptions.

Step 3: Ask it to verify its own answer

After Grok answers, ask it to check the result a different way, by plugging numbers back in or solving by another method. Self-verification catches arithmetic slips that even reasoning mode makes. If the two methods disagree, you know to dig in.

Grok - verification

You

Verify that by computing the distance each train has traveled at the catch-up time.

Agent

At 11:00 the first has gone 120 miles, the second 80 mph for 1h20m = ... they match. Answer confirmed.

Asking Grok to confirm its answer with a second method.

Do not use Think for simple lookups

For quick facts, definitions, or casual chat, leave Think off. It is slower and you gain nothing. Save it for problems where a wrong answer actually costs you.

Result

You get a worked solution with visible steps and a second-method check, which is far more trustworthy than a fast one-line answer. For genuinely hard problems, Think mode is the difference between a guess and a solution.