Estimate Sum or Difference
Remember to use the three benchmarks - 0, 1/2, 1 for your estimate.
4/5 + 5/8
1 1/2
4/9 and 1/3
4/9 and 3/9
5 1/2 + 2 1/8
7 5/8
Estimate the sum of 3/4 and 1/5 then write an equation.
Estimation = 1
3/4 + 1/5 = 19/20 or
15/20 + 4/20 = 19/20
Sandra drove for 1/3 hour to get to the store. Then she drove 1/5 hour to get to the library. What fraction of an hour did Sandra drive in all? Answer with a complete equation.
1/3 + 1/5 = 8/15
or
5/15 + 3/15 = 8/15
Remember to use the three benchmarks 0, 1/2, 1 for your estimate
7/8 - 5/12
1/2
3/5 and 7/10
6/10 and 7/10
7 5/6 - 3 2/3 =
4 1/6
Justin jogs 3 2/5 miles every morning. He jogs 4 6/10 every evening. How many miles does he jog every day? Answer with an equation and a label.
3 2/5 + 4 4/10 = 7 8/10 or 7 4/10 miles
or
3 4/10 + 4 4/10 = 7 8/10 miles
Gilberto worked 3 1/4 hours on Thursday, 4 2/5 hours on Friday, and 6 1/2 hours on Saturday. How many hours did he work in all during the three days?
3 1/4 + 4 2/5 + 6 1/2 = 14 3/20
or
3 5/20 + 4 8/20 + 6 10/20 = 14 3/20
Remember to use the three benchmarks - 0, 1/2, 1 for your estimate.
1/8 + 1/16
0
5/6 and 7/18
15/18 and 7/18
3 3/4 + 1 5/6 =
5 7/12
Tim has 5/12 of a jar of blackberry jam and 3/8 of a jar of strawberry jam. What is the total amount of jam Tim has? Write a complete equation for your answer.
5/12 + 3/8 = 19/24
or
10/24 + 9/24 = 19/24
Mona bought 3 3/8 pounds of cheddar cheese. She used 2 3/4 pounds to make sandwiches. Write and solve an expression to find how much cheese is left. Label your answer.
3 3/8 - 2 3/4
2 11/8 - 2 6/8 = 5/8 pound of cheese
Remember to use the three benchmarks - 0, 1/2, 1 for your estimate.
11/12 - 1/10
0
3/7 and 1/4
12/28 and 7/28
9 - 3/8 =
8 5/8
Benjamin and his sister shared a large sandwich. Benjamin ate 3/5 of the sandwich and his sister ate 1/7 of the sandwich. How much more did Benjamin eat than his sister?
3/5 - 1/7 = 16/35
or
21/35 - 5/35 = 16/35
Mark is making a small framin in the shape of an equilateral triangle. One side of the frame is 3 1/2 inches. What is the perimeter of the equilateral triangle? Make sure to label your answer.
3 1/2 + 3 1/2 + 3 1/2 = 10 1/2 inches
Remember to use the three benchmarks - 0, 1/2, 1 for your estimate.
3/5 - 1/12
1/2
4/25 and 3/75
12/75 and 3/75
(4 3/5 + 7 2/3) - 1 2/5 =
10 13/15
A.) A baker uses food coloring to color cake batter. He needs 4 1/8 ounces of green food coloring. The baker only has 2 1/2 ounces. How much more green food coloring does he needs?
B.) If the baker only finds 1 ounce of food coloring at the store, how many more ounces does the baker need?
A.) 4 1/8 - 2 1/2 = 1 1/8
or 3 5/8 - 2 4/8 = 1 1/8
B.) 1 1/8 - 1 = 1/8
Dawson says that the expression
(2 4/10 + 8 4/5) - 3 1/5 is equal to a whole number.
Do you agree? Explain by showing your work
2 4/10 + 8 4/5 = 10 24/20 or 11 4/20
10 24/20 - 3 4/20 = 8
I agree with Dawson, the answer is a whole number.