Умножение ментально: 1) 5,13×5,6; 2) 35,2×0,49; 3) 87,7×6,9; 4) 2,1×31; 5) 2,29×57.

1. \(5,13\times5,6=28,728\)
2. \(35,2\times0,49=17,248\)
3. \(87,7\times6,9=605,13\)
4. \(2,1\times31=65,1\)
5. \(2,29\times57=130,53\)

Ответ: 28,728; 17,248; 605,13; 65,1; 130,53.