Q1. Simplify the ratio of four dollars to eight dollars.
✔ Divide both parts by four to get the simplest form.
Q2. Which ratio is equivalent to two to three?
✔ Multiply both parts of the original ratio by two.
Q3. Ravi and Siti share money in a ratio of two to three. How many total units are there?
✔ Add the parts together to find the total number of units.
Show transcript
[Slide 1] What Is A Ratio?
Imagine buying chicken rice at a hawker centre. We compare the number of plates using a ratio. This helps us see relationships between amounts clearly.
[Slide 2] Equivalent Ratios Rule
If you double the ingredients, the taste stays similar. In maths, we multiply or divide both parts by the same number. This keeps the ratio equivalent and correct.
[Slide 3] Worked Example Setup
Ravi and Siti are at Tampines MRT station. They share their savings in a ratio of two to three. We draw two bars for Ravi and three for Siti.
[Slide 4] Solving With Bar Model
If their total money is one hundred fifty dollars, we find the value of one unit. We multiply both parts of the ratio by five to match the total. Now Ravi has sixty and Siti has ninety.
[Slide 5] Common Mistake Alert
Students often add one to each part of the ratio incorrectly. Remember, adding changes the relationship between the amounts. You must always scale both parts equally using multiplication.
[Slide 6] PSLE Recap Notes
Always use the bar model to visualise the problem clearly. Check that your equivalent ratios maintain the same value. Good luck with your PSLE preparation this year.