Assuming the paragraphs you want calculated all end with an equal sign, this will add the value after that character.
Code:
Sub MyCalculatorAll()
Dim aChar As Variant, aRng As Range, iTotal As Long, bFlip As Boolean, aPara As Paragraph
For Each aPara In ActiveDocument.Paragraphs
Set aRng = aPara.Range
aRng.End = aRng.End - 1
'aRng.Select 'activate this line to see the progress or testing
If aRng.Characters.Last = "=" Then
iTotal = 0
bFlip = False
For Each aChar In aRng.Characters
Select Case AscW(aChar)
Case 1488 To 1497: iTotal = iTotal + AscW(aChar) - 1487
Case 1498, 1499: iTotal = iTotal + 20
Case 1500: iTotal = iTotal + 30
Case 1501, 1502: iTotal = iTotal + 40
Case 1503, 1504: iTotal = iTotal + 50
Case 1505: iTotal = iTotal + 60
Case 1506: iTotal = iTotal + 70
Case 1507, 1508: iTotal = iTotal + 80
Case 1509, 1510: iTotal = iTotal + 90
Case 1511: iTotal = iTotal + 100
Case 1512: iTotal = iTotal + 200
Case 1513: iTotal = iTotal + 300
Case 1514: iTotal = iTotal + 400
Case 45: iTotal = iTotal * -1: bFlip = True 'a minus sign
End Select
Next aChar
If bFlip Then iTotal = iTotal * -1
aRng.InsertAfter iTotal
End If
Next aPara
End Sub