Unit 12 · Ratio and proportion

Video lessons

4 lessons from established maths channels, all taught by native English speakers and all matched to a specific section of Unit 1. Every video ID was verified, so none of these links are broken.

CorbettmathsMath Antics Math with Mr. JKhan Academy Mathsaurus
This is the one page that needs an internet connection. The players below stream from YouTube. If you are working offline, use the printable PDFs on the downloads page instead, and come back to the videos later.

12.1 Understanding ratio1 videos

Ratio: simplifying

British corbettmaths

Dividing every part by the highest common factor, with the same-units trap included.

Open on YouTube ↗

12.2 Sharing in a ratio2 videos

Ratio: sharing the total

British corbettmaths

The add–divide–multiply method, and the check that the shares total back.

Open on YouTube ↗

Ratio when given one quantity

British corbettmaths

Working backwards: one share is known, the total is not.

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12.3 Direct proportion1 videos

Math Antics - What Percent Is It?

American stretchmathantics

Proportional reasoning in its percentage form — the same idea in different clothes.

Open on YouTube ↗

All links in one tablecopy-friendly

SectionVideoChannelAccentLevel
12.1Ratio: simplifyingcorbettmathsBritishcore
12.2Ratio: sharing the totalcorbettmathsBritishcore
12.2Ratio when given one quantitycorbettmathsBritishcore
12.3Math Antics - What Percent Is It?mathanticsAmericanstretch