1 Read the story
Your story stays on this device. Roji can't read it, so it checks that your bars, equation and answer agree with each other.
- What does the story ask you to find? That amount gets the ?
- What amounts does it give you? Those are your labels.
2 Build the bar model
Example model for this story.
Drag a piece onto a bar, or tap it.
3 Write the equation
Check your model first. Then write an equation that matches your bars.
4 Solve it
Your equation comes first. Then work it out and type your answer.
? =
How bar models work
- A bar is an amount. Parts sit side by side inside it. The label under a bar is the whole bar.
- Parts can be any size. Type a number in a part, or ? for the amount you need to find.
- Equal parts (green) are always the same size and worth the same amount. Use them for equal groups, “times as many”, fractions, ratios and percents.
- Two bars compare two amounts. Make the bigger amount's bar longer, then show the difference.
- A bracket labels a few parts together, like 3 of the 5 equal parts.
- Roji never solves the story for you. It checks that your bars, your equation and your answer agree.