60 + 40 = 100 30 + 40 = 70 60 – 50 = 10 |
500 + 200 = 700 700 – 200 = 500 700 – 500 = 200 |
300 + 600 = 900 900 – 300 = 600 900 – 600 = 300 |
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60+40=100 30+40=70 60-50=10 500+200=700 700-200=500 700-500=200 300+600=900 900-300=600 900-600=300