1. Ratio
1.1. a : b
1.1.1. Order is important.
1.1.2. no units
1.1.3. Actual vs. Relative quantity
1.1.4. simplest form
1.1.4.1. Can both number be divided by:
1.1.4.1.1. 2 ?
1.1.4.1.2. The smaller of the two number?
1.1.4.1.3. 3 ?
1.1.5. Take note of the unit of measurement
1.1.5.1. Bag A is 1kg. Bag B is 500g. What is the ratio of Bag A to Bag B?
1.1.5.1.1. 1000 : 500 = 2 : 1
1.1.6. 'a' and 'b' are whole numbers.
1.1.6.1. 1 : 2
1.2. Equivalent Ratio
1.2.1. Find one quantity given the other quantity and the ratio of two quantities.
1.2.1.1. In 3 : 8 = 21 : g, what is the value represented by G?
1.2.2. Solve up to 2-step word problems involving ratios of two quantities.
1.2.2.1. Lenny and Stephy ate a box of sweets. The ratio of the number of sweets Lenny ate to the number of sweets Stephy ate is 5 : 8. If Stephy ate 40 sweets, how many sweets did Lenny eat?
1.3. a : b : c
1.3.1. Find one quantity given the other quantity and the ratio of three quantities.
1.3.1.1. 6 : 9 : 21 = A : 12 : B What are the values represented by A and B?
1.3.2. Solve up to 2-step word problems involving ratios of three quantities.
1.3.2.1. Aisyah used red, yellow and blue beads to make a necklace. The ratio of number of red beads to the number of yellow beads to the number of blue beads used was 9 : 4 : 7. If there was a total of 260 beads, how many more red than blue beads did she used?
1.4. Unitary Method of Problem Solving
1.4.1. Start and End of Question Stem
1.4.1.1. Mark and Sharon have some postcards in the ratio 2 : 3
1.4.1.2. 2/5 of the postcards belong to Mark and 3/5 of the postcards belong to Sharon.
1.4.1.3. 1/2 of Mark’s postcards is equal to 1/3 of Sharon’s postcards.
1.4.1.4. Mark has 2/3 as many postcards as Sharon.
1.4.2. Type of changes
1.4.2.1. One party unchanged
1.4.2.1.1. Sharon buys another 15 postcards [Mark remains unchanged]
1.4.2.2. Total unchanged
1.4.2.2.1. Mark gives 5 postcards to Sharon [total remains unchanged]
1.4.2.3. Difference unchanged
1.4.2.3.1. Mark and Sharon gives away 25 postcards each [difference remains unchanged]
1.4.2.3.2. Age Gap
2. Area of Triangles
2.1. Identify the base of a triangle and its corresponding height.
2.1.1. The breath of a triangle can be any of the sides of the triangle
2.1.2. The height of the triangle is a perpendicular line segment from the base to the opposite vertex of the triangle.
2.1.3. The height need not be inside the triangle.
2.2. Use formula to find the area of a triangle
2.2.1. Example 1:
2.2.2. Example 2:
2.2.3. Example 3: