How to solve this age probem - ration using singapore mathematics?

Question

I am new to Singapore mathematics. I could solve this question very easily using algebra. However, I feel that you get a good picture - conceptually when you try to solve questions using singapore mathematics. The variables x,y - algebra hide the deep understanding. Do you agree? Can you share me some right books - singapore mathematics -- links to start understanding singapore maths so that I can solve any complex problem without using algebra. Anyway, here is my question that I am trying to solve using singapore mathematics.

Present ages of Sameer and Anand are in the ratio of $5 : 4$ respectively. Three years hence, the ratio of their ages will become $11 : 9$ respectively. What is Anand's present age in years?

Answer 1

$\overbrace{\begin{array}{|c|c|c|c|c|c|c|c|c|c|c|}\hline & & & & & & & & & & \hline\end{array}}^{\text{Sameer's age in 3 years}}$

$\overbrace{\begin{array}{|c|c|c|c|c|c|c|c|c|}\hline & & & & & & & & \hline\end{array}}^{\text{Anand's age in 3 years}}$

We must remove the same amount of boxes (representing 3 years) so as to get a ratio of $5:4$. Removing one box should do it. So one box is $3$ years. Sameer is currently $30$; Anand is $24$.

Answer 2

Let be $S$ and $A$ the current ages of Sameer and Anand and rephrase the words.

So, today $$\frac{S}{A}=\frac{5}{4}$$ In three years time from now, we shall have $$\frac{S+3}{A+3}=\frac{11}{9}$$

I am sure that you can take from here.