Solving Mentally
Solve m - 5 = 2 mentally.
7
Solve x + 4 = 5. Check your solution.
x = 1
Solve x - 5 = 10. Check your solution.
x = 15
Solve 6x = 18. Check your solution.
x = 3
Solve p/7 = 5. Check your solution
p = 35
Is 5, 6, or 7 the solution of the equation 4 + b = 10?
6
Solve d + 3 = 8. Check your solution.
Solve r - 3 = 1. Check your solution.
r = 4
Solve 4x = 24. Check your solution.
x = 6
Solve 4 = r/8. Check your solution.
r = 32
Solve 20 divided by d = 5 mentally.
4
Solve 7 = 4 + y. Check your solution.
y = 3
Solve r - 4 = 16. Check your solution.
r = 20
Solve 21 = 3g. Check your solution.
g = 7
Solve x/7 = 8. Check your solution.
x = 56
Kevin has 60 baseball cards. There are 10 baseball cards in each package. Solve the equation 10 x b = 60 to find b, the number of packages of cards Kevin has.
6 packages.
Pennsylvania is 280 miles from east to west. This is 120 miles more than then length of the state from north to south. Write and solve an equation to find the length of Pennsylvania from north to south.
x + 120 = 280; 160 miles
After you withdraw $50 from your savings account, the balance is $124. Write and solve a subtraction equation to find your starting balance.
b - 50 = 124; $174
Thomas uses 4 cups of flour to make 2 loaves of banana bread. Write and solve a multiplication equation to find the number of cups of flour that are needed to make one loaf of bread.
2x = 4; 2 cups
One fourth of the number of students in the sixth grade participate in an after-school sport. If 42 students play sports, write and solve a division equation to find the number of students in the sixth grade.
s/4 = 42; 168 students
Devin and Hannah have 72 marbles together. Hannah has 12 marbles. Solve the equation 72-b = 12 to find d, the number of marbles that Devin has.
60 marbles.
Julie and Len went swimming. Julie swam 575 meters. This is 150 more meters than Len swam. Write and solve an addition equation to find the number of meters that Len swam.
150 + x = 575; 425 meters
The difference between the number of people that visit an amusement park on a Saturday and the number of people that visit the park on a Wednesday is 1,465. There are 4,320 visitors on Wednesday. How many visitors are there on Saturday? Write and solve a subtraction equation.
1,465 = x - 4,320; 5,785 visitors.
The Raimonde family drove 1,764 miles across the United States on their vacation. If it took a total of 28 hours, write and solve a multiplication equation to find their average speed in miles per hour.
1,764 = 28r; r = 63 miles per hour
b/18 = 4; 72 inches