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Word problemsArithmeticMiddle schoolabout 0:45

A number increased by 12 is 31. Find the number: animated lesson

A narrated, step-by-step word problems video lesson with captions. Final answer: The number is 19.

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Video with a synthetic English voice and captions. Pick another language for subtitles in that language, or open the interactive version.

Video narrated by a synthetic voice (Piper TTS, en_US-ljspeech-high voice (LJ Speech dataset, public domain)); the steps come from our maths engine and the answer was checked independently. Download MP4 (0.3 MB) · Captions (WebVTT)

Steps on screen

1. The problem
Worked example
A number increased by 12 is 31. Find the number.
2. Step by step
1. Read the problem
2. Solve the linear equation
3. The answer
$\text{The number is 19}$
The number is 19
4. Check
- Substitute x = 19: (19) + 12 = 31 ✓

Transcript

The problem. Here is the problem: A number increased by 12 is 31. Find the number. Let x be the number: “a number increased by 12” becomes x plus 12.

Step by step. Read the problem. Let x be the unknown number. “a number increased by 12 is 31” translates to x plus 12 equals 31. Solve the linear equation. 1x plus 12 equals 31 → x equals (31 minus 12) / 1 equals 19.

The answer. So the answer is The number is 19. Let x be the number: “a number increased by 12” becomes x plus 12.

Check. Substitute x equals 19: (19) plus 12 equals 31, which checks out.

About word problems

Turn everyday situations about prices, speed, ages and interest into equations and solve them.

A number increased by 12 is 31. Find the number (Lesson)