72-18=54; 540÷9=60; 23-18=5; 69÷3=23;
2000÷5=400; 63÷7=9; 12×4=48; 480÷4=120;
48+35=83; 180÷3=60; 18×4=72; 82÷2=41;
32-15=17; 630÷9=70; 18+36=54; 100÷5=20.
72-18=54; 540÷9=60; 23-18=5; 69÷3=23;
2000÷5=400; 63÷7=9; 12×4=48; 480÷4=120;
48+35=83; 180÷3=60; 18×4=72; 82÷2=41;
32-15=17; 630÷9=70; 18+36=54; 100÷5=20.