Add & Subtract Decimals with Rounding & Estimating

Front

What is a decimal?

Back

A decimal is a number that includes a decimal point, which separates the whole number part from the fractional part. For example, 3.14 is a decimal.

Front

How do you add decimals?

Back

To add decimals, align the decimal points and add as you would with whole numbers. Place the decimal point in the answer directly below the other decimal points.

Front

What is rounding?

Back

Rounding is the process of adjusting the value of a number to make it simpler while keeping it close to the original value. For example, rounding 4.7 to the nearest whole number gives 5.

Front

How do you round a decimal to the nearest whole number?

Back

Look at the digit to the right of the decimal point. If it is 5 or greater, round up. If it is less than 5, round down.

Front

What is estimating in math?

Back

Estimating is finding a number that is close enough to the exact answer, often used to make calculations easier.

Front

How do you subtract decimals?

Back

To subtract decimals, align the decimal points and subtract as you would with whole numbers. Place the decimal point in the answer directly below the other decimal points.

Front

What is the difference between exact and estimated answers?

Back

An exact answer is the precise result of a calculation, while an estimated answer is a close approximation that is easier to work with.

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What is the process to find change from a purchase?

Back

To find change, subtract the total cost from the amount paid. For example, if you pay $10 for a $5.74 bill, the change is $10 - $5.74 = $4.26.

Front

How do you estimate the sum of two decimals?

Back

Round each decimal to the nearest whole number and then add those rounded numbers together.

Front

What is the importance of aligning decimal points?

Back

Aligning decimal points ensures that you are adding or subtracting the correct place values, which is crucial for accurate calculations.