Download Rounding Numbers

Rounding Numbers
Learning Goals
• LG: Demonstrate the ability to round numbers
to the nearest tenth, hundredth, and
thousandth
• Kid friendly: Show that you can round
numbers to tenths, hundredths, and
thousandths
Definitions
• Rounding: Rounding means reducing the digits
in a number while trying to keep its value
similar. The result is less accurate, but easier
to use.
• Example: 73 rounded to the nearest ten is 70,
because 73 is closer to 70 than to 80.
Number Lines
• Using a number line can be helpful when
rounding. You always want to round to the
number closest to the number you are at.
• When the number is five, you round up
Practice
Number makeover
• Create a number with three digits after the
decimal place by rolling the dice 4 times
• My number:
• Let’s round to the nearest thousandth
• Now to the nearest hundredth
• Now to the nearest tenth
• And now to the nearest whole.
• My number went from to
Rounding
• Math Practice Examples
5. a) 88.0
b) 45.23 45.2
c) 24.99 25.0
Estimation/Comparing Decimals
• With whole numbers it is easy to see which
number is greater than the other. How can
you tell right away?
– How do you know 23 is less than 132?
• 0.021 < 0.2
• Think of at least three examples by rolling the
dice
Template
• On the top piece of paper write
– Your # < or > Your other #
– Ex:
• On the bottom piece of paper write “How do I
know this?”
In Between Decimals
• Use the number line sheet you were provided
with
• What are the decimals that fall between…
Between 3.2 and 3.6
Between 3.2 and 3.3
Between 3.2 and 3.21
For decimals between For decimals between For decimals between
3.2 and 3.6 you look to 3.2 and 3.3 you look to 3.2 and 3.21 you look
the tenths
the hundredths
to the thousandths