Simple math that makes most sense


The back story

My 2-year-old almost every day stops over at the ‘Turtle Aunty Home’. After play time, he asks to make a pit stop on a floor below ours where this aunty has a pet turtle. He loves to watch the reptile respond to sounds, eat its given food and take its head out when it wants.

Yesterday, we reached her door. Even before we could ring the bell, ‘Turtle Aunty’ opened it to let a few children out of her home. Kids with heavy back packs and very solemn countenance made way into the lift. Aunty welcomed us in and while my son enjoyed his turtle time, the two of us got chatting. I learnt that it was a math tuition class called almost as an emergency since the next day was exam day. The class will assemble again next day to analyze the questions in the paper. I was impressed with her dedication. More chatting ensued as aunty went on to talk about her love for math.

The story of passion

She said she had always topped math exams in her school and made sure her daughters continued the winning streak. There were trophies of various sizes decorating her living room. As a child, she enjoyed the tag of a ‘bright student’ by family and friends. After her marriage too, her in-laws were won over in no time as they got to know about her fluency with the subject.

I heard her tale of passion and in my awe, asked her how she calculates her finances like budgeting and investing. Who else than a math whiz could excel in it. Suddenly, Aunty drew a blank. For a second, I thought I asked a wrong question. After a moment, she said that money management is done by her husband. He allocates monthly expenses to her which is the only part she manages.

Sigh! The tale of passion was now a tale of disbelief. “Never mind”, I thought and asked her for a glass of water. Such a capable lady deserves to do much more. And I couldn’t let the opportunity pass, to tell her that. Yes, it was time to introduce her to the real math – the 50-30-20 math.

The Real Math

We all broadly know what we want money to do for us. We just have to spell it out in what is called as short-term and long-term goals. These goals have to be achieved with some bit of planning. You have to do budgeting smartly to your monthly income post taxes.

50% of Your income – Essentials

To begin abiding by this rule, set aside no more than half of your income for the absolute necessities in your life. In general, these expenses would include housing, food, transportation costs and utility bills.

30% of your income – Discretionary

This is the category that can bring the difference. It’s the part you spend on your lifestyle and therefore the more you keep this in check, the better you can channel towards goal achievements and future.

20% of your income – Savings

This part should be non-negotiable. You have to allocate this amount to savings & investments after taking care of your loans and other debts. This is the part that makes your net worth / corpus / portfolio and will take care of goals.
While documenting my experience yesterday, I found this very simple representation of the rule.


Aunty grasped everything in no time and had a few doubts to ask. I was extremely happy she took keen interest. Little man however, had his fill of the turtle and asked to be taken home. Aunty and I promised each other to continue our discussion later.

Now its me who can’t wait to make a pit stop at the ‘Turtle Aunty Home’.