Estimating
Properties of Addition
Adding Decimals
Subtracting Decimals
Applications
Rounding
100
Estimate 9.74 + 111.06 by rounding to the nearest whole number.
121
100
Identify the addition property shown below:
(14 + 26) + 91 = 14 + (26 + 91)
Associative Property of Addition
100
19.23 + 0.099=
19.329
100
2.5 - 0.79 =
1.71
100
Mrs. Tyson's math class held a bake sale to earn money to pay for a field trip. The field trip costs $350 total. During the bake sale, the pies generated $78.50, the cookies made $122.25, and the cakes brought in $95.75. How much more money does the class need to earn to pay for the field trip?
The class needs to earn $53.50 more.
100
Round to the place listed:
6.631; ones
7
200
Estimate 7.32 - 0.53 by rounding to the highest place.
6.5
200
Identify the addition property shown below:
32 + 45 + 8 = 32 + 8 + 45
Commutative Property of Addition
200
5.79 + 21.9 =
27.69
200
19.23 - 7.27 =
11.96
200
Jane collected 20.78 pounds of Halloween candy while trick or treating. Davis has 16.45 pounds of candy. About how much more candy does Jane have than Davis?
21-16=5
Jane has about 5 more pounds of candy than Davis.
200
Round to the place listed:
115.67; tenths
115.7
300
Estimate 188.78 - 63.2 by rounding to the highest place.
140
300
Identify the addition property shown below:
46.17 + 0 = 46.17
Identity Property of Addition
300
212.1 + 87.648 =
299.748
300
14.3 - 6.88 =
7.42
300
For a school project, three students recorded how much water they drank each day for 3 days. Their results are shown in the Water Journal table.
Bria set a goal to drink 10 litres of water each week. How much more water should Bria drink to meet her goal?
1.06 + 0.96 + 0.97 = 2.99 litres
10 .00 - 2.99 = 7.01 litres
Bria needs to drink 7.01 litres more throughout the rest of the week.
300
717.28; hundreds
700
400
Round to the place listed:
0.049; highest place
0.05