Rounding

1
Rounding

• You can be asked to round to the nearest
• the nearest whole number,
• the nearest ten/ hundred etc,
• a specified number of decimal places,
• a specified number of significant figures

2
357.956 to 2 decimal places

• To round mark where you are rounding to.
• 357.956
• If the next number down is 5 or more, your marked
  number goes up one. 357.956
• 357.96 to 2 dp.

357.956 to 1 decimal places
357.956 358.0 to 1 dp.
The 0 is important
3
1359.834

• 1359.83 to 2 dp
• 1359.8 to 1dp
• 1360 to nearest whole number
• 1360 to nearest ten
• 1400 to nearest hundred
• 1000 to nearest thousand

4
Significant figures

• The furthest left non zero number is your first
  significant figure.
• e.g 596.32 0.003296 4002
• The next one right is the second sig fig and so
  on.

3rd sig fig
4002
2nd sig fig
1st sig fig
5
To 3 Significant figures

• 596.32 596
• 0.003296 0.00330
• 4002 4000
• So a number to 3 significant figures can have
  more than 3 digits if zeros are required to keep
  the value of the number