Grade 5 · Unit 1: Number and place value

Millions, crore and thousandths

From very big to very small.

The population of Bangladesh

Bangladesh has about 17 crore people – about 170 million. Big numbers like this need millions and crores. Small measurements need thousandths.

Millions

Each place is 10 times the place to its right. Read in groups of three: 4 million, 307 thousand, 520. In South Asian style: 43,07,520 – 43 lakh, 7 thousand, 520.

Two systems

1 million = 10 lakh. 1 crore = 10 million. News in Bangladesh often uses lakh and crore.

Thousandths

After hundredths comes thousandths. 2.375 kg = 2 kg and 375 g. Multiplying by 10, 100 or 1000 moves digits left; dividing moves them right.

Billions

A billion is 1 000 000 000 – a thousand million, or 100 crore. The world has about 8 100 000 000 people: ten digits! Compare big numbers by their number of digits first, then the biggest place.

What I learnt

• I can read numbers to millions and crore.
• I can read decimals to thousandths.
• I can multiply and divide by powers of 10.