...blok 2 contractwerk.gif hoofdrekenen... oefening 4

10 + 100 =
1 000 - 10 =
900 - 40 =
600 + 60 =
70 + 700 =
50 + 105 =
750 - 250 =
180 - 150 =
1 000 - 650 =
90 + 950 =