add
what is 500+30
530
what is 30-10
20
what is a 4 sided shape
square
what is 900+90
990
what is 20-10
10
what is a 5 sided shape
pentagon
what is 50+40
90
what is 50-10
40
what is a 3 sided shape
triangle
what is 90+10
100
what is 80-40
40
what is a shape with 4 sides
trapizoid
what is 100+1000
1100
what is 90-50
40
name a shape with 6 sides
hexagon