Across
1
Total distance around a shape
4
System of ordered marks for measuring
6
Repeated addition
8
The number representing nothing
9
Line touching circle at one point
Down
1
U-shaped curve of a quadratic function
2
Amount of space an object occupies
3
Number that divides evenly into another
4
Steepness of a line
5
Result of addition
7
Distance from center to edge of circle