Question

calculeaza in scris si efectuaza proba prin adunare repetata 42×2..31×3...12×4 ..30×4 ..44×3...21×5..18×3?​

Answer 1

42×2=84

42+42=84

31×3=93

31+31+31=93

12×4=48

12+12+12+12=48

30×4=120

30+30+30+30=120

44×3=132

44+44+44=132

21×5=105

21+21+21+21+21=105

18×3=54

18+18+18=54

Answer 2

42×2=84

Prin adunare:42+42=84

31×3=93

Prin adunare:31+31+31=62+31=93

12×4=48

Prin adunare:12+12+12+12=24+24=48

30×4=120

Prin adunare:30+30+30+30=60+60=120

44×3=132

Prin adunare:44+44+44=88+44=132

21×5=105

Prin adunare:21+21+21+21+21=42+42+21=84+21=105

18×3=64

Prin adunare:18+18+18=64