Выполни действия: a) 90 ⋅ 400 б) 7 ⋅ 8000 в) 3000 ⋅ 20 г) 600 ⋅ 900 д) 160 ⋅ 500 е) 2000 ⋅ 350 ж) 80 ⋅ 600 з) 15 ⋅ 4000

Выполним умножение круглых чисел:

1. a) 90 ⋅ 400 = 9 ⋅ 4 ⋅ 10 ⋅ 100 = 36 ⋅ 1000 = 36000
2. б) 7 ⋅ 8000 = 7 ⋅ 8 ⋅ 1000 = 56 ⋅ 1000 = 56000
3. в) 3000 ⋅ 20 = 3 ⋅ 2 ⋅ 1000 ⋅ 10 = 6 ⋅ 10000 = 60000
4. г) 600 ⋅ 900 = 6 ⋅ 9 ⋅ 100 ⋅ 100 = 54 ⋅ 10000 = 540000
5. д) 160 ⋅ 500 = 16 ⋅ 5 ⋅ 10 ⋅ 100 = 80 ⋅ 1000 = 80000
6. е) 2000 ⋅ 350 = 2 ⋅ 35 ⋅ 1000 ⋅ 10 = 70 ⋅ 10000 = 700000
7. ж) 80 ⋅ 600 = 8 ⋅ 6 ⋅ 10 ⋅ 100 = 48 ⋅ 1000 = 48000
8. з) 15 ⋅ 4000 = 15 ⋅ 4 ⋅ 1000 = 60 ⋅ 1000 = 60000

Ответ: a) 36000; б) 56000; в) 60000; г) 540000; д) 80000; е) 700000; ж) 48000; з) 60000