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Order of operationsArithmeticElementary schoolabout 0:44

Evaluate 7/2-1: animated lesson

A narrated, step-by-step order of operations video lesson with captions. Final answer: 5/2.

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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
7/2-1
2. Step by step
1. $\frac{7}{2} - 1 = \frac{7}{2} - \frac{2}{2}$
  Rewrite both fractions with the least common denominator
2. $\frac{7 - 2}{2} = \frac{5}{2}$
  Subtract the numerators and keep the denominator
3. $\frac{5}{2} = 2\tfrac{1}{2}$
  Final answer in lowest terms
3. The answer
$\frac{5}{2}$
7/2-1 = 5/2
4. Check
- Decimal check: 5/2 ≈ 2.5
- As a mixed number: 2 1/2

Transcript

The problem. Here is the problem: 7 over 2 minus 1. Exact arithmetic with fractions (results kept in lowest terms).

Step by step. Rewrite both fractions with the least common denominator. The LCD of 2 and 1 is 2. Subtract the numerators and keep the denominator. Final answer in lowest terms.

The answer. So the answer is 5 over 2. 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: 5 over 2 approximately 2.5. As a mixed number: 2 1 over 2.

About order of operations

Evaluate expressions with brackets, powers, multiplication, division, addition and subtraction in the right order.

Evaluate 7/2-1: Order of operations Step-by-Step Lesson