Найди значения произведений: a) 30 ⋅ 50 б) 70 ⋅ 90 в) 8 ⋅ 300 г) 600 ⋅ 5 д) 800 ⋅ 8 е) 3 ⋅ 7000 ж) 60 ⋅ 40 з) 200 ⋅ 6

Выполним умножение круглых чисел:

1. a) 30 ⋅ 50 = 3 ⋅ 5 ⋅ 10 ⋅ 10 = 15 ⋅ 100 = 1500
2. б) 70 ⋅ 90 = 7 ⋅ 9 ⋅ 10 ⋅ 10 = 63 ⋅ 100 = 6300
3. в) 8 ⋅ 300 = 8 ⋅ 3 ⋅ 100 = 24 ⋅ 100 = 2400
4. г) 600 ⋅ 5 = 6 ⋅ 5 ⋅ 100 = 30 ⋅ 100 = 3000
5. д) 800 ⋅ 8 = 8 ⋅ 8 ⋅ 100 = 64 ⋅ 100 = 6400
6. е) 3 ⋅ 7000 = 3 ⋅ 7 ⋅ 1000 = 21 ⋅ 1000 = 21000
7. ж) 60 ⋅ 40 = 6 ⋅ 4 ⋅ 10 ⋅ 10 = 24 ⋅ 100 = 2400
8. з) 200 ⋅ 6 = 2 ⋅ 6 ⋅ 100 = 12 ⋅ 100 = 1200

Ответ: a) 1500; б) 6300; в) 2400; г) 3000; д) 6400; е) 21000; ж) 2400; з) 1200