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FractionsArithmeticElementary schoolabout 0:42

Calculate 3/10 + 2/5: animated lesson

A narrated, step-by-step fractions video lesson with captions. Final answer: 7/10.

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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
3/10 + 2/5
2. Step by step
1. $\frac{3}{10} + \frac{2}{5} = \frac{3}{10} + \frac{4}{10}$
  Rewrite both fractions with the least common denominator
2. $\frac{3 + 4}{10} = \frac{7}{10}$
  Add the numerators and keep the denominator
3. $\frac{7}{10}$
  Final answer in lowest terms
3. The answer
$\frac{7}{10}$
3/10 + 2/5 = 7/10
4. Check
- Decimal check: 7/10 ≈ 0.7

Transcript

The problem. Here is the problem: 3 over 10 plus 2 over 5. Exact arithmetic with fractions (results kept in lowest terms).

Step by step. Rewrite both fractions with the least common denominator. The LCD of 10 and 5 is 10. Add the numerators and keep the denominator. Final answer in lowest terms.

The answer. So the answer is 7 over 10. Fractions are combined over a common denominator for addition and subtraction, multiplied straight across, and divided by multiplying by the reciprocal. The result is reduced by the greatest common factor.

Check. Decimal check: 7 over 10 approximately 0.7.

About fractions

Add, subtract, multiply and divide fractions, finding common denominators and simplifying the result.

Calculate 3/10 + 2/5: Fractions Step-by-Step Lesson