In a class, 1 pupil walks to school for every 3 who get a lift. Roughly what fraction of the class walk? And if the class had 100 pupils, about how many would that be?

Three ratios come up on the battery bar, each one shown as a fraction and as a percentage. The filled bar is the first part and the empty bar is what is left. Watch how the two parts of every ratio add back up to 100%, then say which part is bigger in a 3:7 ratio and why, before we check it together.

Now we work three ratios together on the slider: first 1:1, then 1:4, then 3:2. No pencils yet, and nothing to write here — the writing comes next in your copy. For each ratio you say the total number of parts aloud, name the first part as a fraction, and say what percentage that is. One of you will set the slider to that percentage, and the rest of you agree or correct out loud before you read off the empty part and check the two make 100%.