# Decimals

Contents

A dot represents a decimal point. In real life problems like measuring of length, weight, or time, the values are not exact whole numbers but rather portions of whole number. In situations where we need to be exact, we use decimal numbers.

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A dot represents a decimal point. In real life problems like measuring of length, weight, or time, the values are not exact whole numbers, but rather portions of whole numbers. In situations where we need to be exact, we use decimal numbers. In this chapter we will learn how to reduce number to 10ths, 100ths of a decimal place, to compare decimal numbers. We will also learn how to add and subtract decimal numbers, and understand how to use them in real life situations.

One block divided into 10 equal parts means each part is 1/10 (one-tenth) of a unit, and similarly, each block divided into 100 equal parts means each part is 1/100 (one-hundredth) of a unit.

We first compare the whole part, and if it is the same, then the fractional part is compared to arrive at a conclusion. In this topic we will compare decimals by difference in largest place value, ordering from least to greatest, and ordering from smallest to biggest.

Money (1 paisa = Rs.0.01), Length (1 cm=0.01 m), Weight (1 g = 0.001 kg). In this topic we will consider real life problems of measurement and see how the concept of decimals can be applied in converting centimeters to meters, gram to kilogram etc.

To add decimals, we add them as though they are regular numbers, and then we place the decimal at its original position in the result. For example, 0.56 + 1.22 = 1.78. In this topic, we will practice a few problems of decimal addition to get a better understanding of this topic.

To subtract decimals, we keep the decimal point in place, and simply subtract each digit like we would for regular subtraction problems. For example, 2.58 – 1.32 = 1.26. In this topic we will practice a few problems based on decimal subtraction to get a better understanding of the topic.