Transcript I can make reasonable estimates to a situation using whole numbers

I can make reasonable
estimates to a situation using
whole numbers and fractions.
Rachel A. Darnell
To estimate a fraction, you must decide
one of the following.
IS THE FRACTION CLOSEST TO
0 OR 1/2 OR 1
10
12
5
6
3
11
1
3
7
8
2
5
1
8
10
11
SOMETIMES A PICTURE HELPS
Round each fraction to 0 or 1/2 or 1
0
0
0
0
1/2
1/2
4/12 should be rounded to _________
1/2
1/2
6/10 should be rounded to _________
1
6/7 should be rounded to _________
1/2
0
1/12 should be rounded to _________
1
1
1
1
Round a fraction to 0 or 1/2 or 1
0
1/2
0
2/12 should be rounded to _________
3
2 10/12 should be rounded to _________
1
Janice had 7 and 3/4 cups of flour in
a container. She used 3 and 1/4
cups to make cookies. About how
much did she have LEFT in the
container after making cookies?
Step 1 - Round the mixed numbers to the nearest whole
number.
7 3/4 rounds to 8
3 1/4 rounds to 3
Step 2 - Decide on an operation SUBTRACT
Step 3 - Do the computation
8 - 3 = 5 cups of flour
Step 4 - Subtract using the real numbers.
7 3/4 - 3 1/4 = 4 2/4 or 4 and a half cups of flour
Step 5 - Compare your real answer with the
estimate and decide if it is reasonable. REASONABLE
Three friends had a slumber party. Greg
ate 3 and 1/8 candy bars, Brad ate 2 and
6/8 candy bars and Warren ate 1 and 7/8
candy bars. About how many candy bars
did they eat altogether?
Step 1 - Round the mixed numbers to the nearest whole number
3 1/8 rounds to 3
2 6/8 rounds to 3 1 7/8 rounds to 2
Step 2 - Decide on an operation ADD (why)
Step 3 - Do the computation
3 + 3 + 2 = 8 candy bars
Step 4 - Add using the real numbers.
3 1/8 + 1 7/8 = 5 5 + 2 6/8 = 7 6/8 candy bars
Step 5 - Compare your real answer with the
estimate and decide if it is reasonable. REASONABLE
Remember
you estimate
should
always be
__________________
REASONABLE