Solve a problem

Word problemsArithmeticMiddle schoolabout 0:47

If 4 pens cost $6, how much do 10 pens cost?: animated lesson

A narrated, step-by-step word problems video lesson with captions. Final answer: 10 pens cost $15.00.

SpeedLanguage

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
If 4 pens cost 6, how much do 10 pens cost?
2. Step by step
1. Read the problem
2. Unit price
3. Scale to the new quantity
3. The answer
$\text{10 pens cost \$15.00}$
$15.00
4. Check
- $15.00 ÷ 10 = $1.50 per pen, the same unit price ✓

Transcript

The problem. Here is the problem: If 4 pens cost 6, how much do 10 pens cost? Proportion: 4 pens cost 6.00; find the cost of 10.

Step by step. Read the problem. 4 pens for 6.00. Unit price. 6.00 divided by 4 equals 1.50 per pen. Scale to the new quantity. 10 times 1.50 equals 15.00.

The answer. So the answer is 10 pens cost 15.00. Find the price of one unit, then multiply by the quantity you need.

Check. 15.00 divided by 10 equals 1.50 per pen, the same unit price, which checks out.

About word problems

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

If 4 pens cost $6, how much do 10 pens cost? (Lesson)