# Rounding is done in two main ways. 1. Decimal Places 2. Significant Figures.

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Rounding is done in two main ways. 1. Decimal Places 2. Significant Figures

A question might tell you to round a number to 2dp, or 2 decimal places. This means that they want the answer to have __ digits after the decimal place. 3dp = __ digits 12dp = __ digits etc… 2 3 12

Step 1:Draw a line after the number of decimal places you want. e.g.Round 5.378245 to 3dp 23.222756 to 1dp 12.735691 to 4dp 200.11658 to 2dp

Step 2:If the next number after the line is low (0, 1, 2, 3, 4) then ignore everything after the line. e.g.Round 5.378245 to 3dp  5.378 23.222756 to 1dp  23.2 12.735691 to 4dp 200.11658 to 2dp

Step 3:If the next number after the line is high (5, 6, 7, 8, 9) then add one to the number to the LEFT of the line e.g.Round 5.378245 to 3dp 23.222756 to 1dp 12.735691 to 4dp  12.7357 200.11658 to 2dp  200.12

Instead of a number of decimal places you can count every digit in the number except any zeros at the start or end of the number. When you round to significant figures you draw your line after that many digits. It is written as sf rather than dp

e.g.Round 253.5283 to 4sf 1929 to 3sf 12.84582 to 2sf 0.0034767 to 3sf 0.7561123 to 4sf 0.00591987 to 1sf 253.5 1930 13 0.00348 0.7561 0.006

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