subtraction
90-0=?
Answer: 90
100+100=?
Answer: 200
100x3=?
Answer: 300
100/5=?
Answer: 20
100-100=?
Answer: 0
200+30=?
Answer: 230
200+45=?
Answer: 245
Answer: 40
300-45=?
Answer: 255
300+67=?
Answer: 367
300x2=?
Answer: 600
300/6=?
Answer: 50
400-67=?
Answer:333
478+47=?
Answer: 525
400x2=?
Answer: 800
400/5=?
Answer: 80
500-50=?
Answer: 450
500+100=?
Answer: 600
500x1=?
Answer: 500
500/5=?
Answer: 100