adding signed numbers
Subtracting signed numbers
equations ax_b=c
equation a(x+b)=c
Riddles
100

3 + -2=

1

100

6 -7

-1 

100

Solve for x

3x + 4 = 7

x = 1 

100

Solve for x

3 (x - 3 ) = 27 

x=12

100

How many months of the year have 28 days?

all months 

12 

200

7 + -10 =

-3 

200

-12 - -2 

-10 

200

Solve for x

5x - 7 = 23

x = 6 

200

Solve for x

5(x-3) = 20

x = 7

200


It belongs to you, but your friends use it more. What is it?



Your name !

300

-3 + -4 

-7

300

5 - - 5 

10 

300

Solve for x

-3 x + 2 = 14

x = -4 

300

Solve for x

-5 (x - 8 ) = -20 

x = 12

300

The more you take, the more you leave behind. What am I?

 Footsteps

400

-8 -8 

-16 

400

3 + -6 

-3

400

Solve for x

-4x - 3 = -11

x=2

400

Solve for x

4(x + 9) = -4 

x = -10 

400

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

A map 

500

-8 + -5 + 13

0

500

-3 + -4 - - 5 

-2 

500

Solve for x

5x + 7 = 2 

x =-1

500

Solve for x

-7 (x + 13 ) = - 21 

x = -10 

500

I have keys but open no locks. I have space but no room. You can enter but not go outside. What am I?

A keyboard or piano