diff --git a/beautiful-racket-demo/algebra-demo/grammar.rkt b/beautiful-racket-demo/algebra-demo/grammar.rkt
index 7668cee..0bb4b17 100644
--- a/beautiful-racket-demo/algebra-demo/grammar.rkt
+++ b/beautiful-racket-demo/algebra-demo/grammar.rkt
@@ -2,5 +2,5 @@
 
 top : (fun | app)*
 fun : /"fun" ID /"(" ID [/"," ID] /")" /"=" expr
-expr : ID "+" ID | app
+expr : ID /"+" ID | app
 app : ID /"(" (ID | INT) [/"," ID] /")"
\ No newline at end of file
diff --git a/beautiful-racket-demo/algebra-demo/main.rkt b/beautiful-racket-demo/algebra-demo/main.rkt
index e8dd255..b11ff54 100644
--- a/beautiful-racket-demo/algebra-demo/main.rkt
+++ b/beautiful-racket-demo/algebra-demo/main.rkt
@@ -9,7 +9,7 @@
   (:or "fun" "(" ")" "=" "+" ","))
 
 (define tokenize-1
-  (lexer
+  (lexer-srcloc
    [whitespace (token lexeme #:skip? #t)]
    [(from/stop-before "#" "\n") (token 'COMMENT #:skip? #t)]
    [reserved-toks lexeme]
@@ -23,12 +23,13 @@
   [(_ VAR ARG0 ARG1 EXPR) #'(define (VAR ARG0 ARG1) EXPR)])
 
 (define-macro-cases expr
-  [(_ LEFT "+" RIGHT) #'(+ LEFT RIGHT)]
+  [(_ LEFT RIGHT) #'(+ LEFT RIGHT)]
   [(_ OTHER) #'OTHER])
 
 (define-macro app #'#%app)
 
 (define (read-syntax src ip)
+  (port-count-lines! ip)
   (define parse-tree (parse src (λ () (tokenize-1 ip))))
   (strip-bindings
    (with-syntax ([PT parse-tree])
diff --git a/beautiful-racket-demo/precalc-demo/grammar.rkt b/beautiful-racket-demo/precalc-demo/grammar.rkt
index 53b07e7..22861cc 100644
--- a/beautiful-racket-demo/precalc-demo/grammar.rkt
+++ b/beautiful-racket-demo/precalc-demo/grammar.rkt
@@ -3,9 +3,9 @@
 top : (fun | app)*
 fun : /"fun" var /"(" argvars /")" /"=" expr
 /argvars : [var (/"," var)*]
-@expr : s-or-d
-s-or-d : [s-or-d ("+" | "-")] p-or-q
-p-or-q : [p-or-q ("*" | "/")] value
+@expr : add-or-sub
+add-or-sub : [add-or-sub ("+" | "-")] mult-or-div
+mult-or-div : [mult-or-div ("*" | "/")] value
 @value : var | INT | app | /"(" expr /")"
 app : var /"(" [expr (/"," expr)*] /")"
 @var : ID
\ No newline at end of file
diff --git a/beautiful-racket-demo/precalc-demo/main.rkt b/beautiful-racket-demo/precalc-demo/main.rkt
index 4958c41..55baee3 100644
--- a/beautiful-racket-demo/precalc-demo/main.rkt
+++ b/beautiful-racket-demo/precalc-demo/main.rkt
@@ -1,6 +1,6 @@
 #lang br/quicklang
 (require brag/support "grammar.rkt")
-(provide top fun app s-or-d p-or-q)
+(provide top fun app add-or-sub mult-or-div)
 
 (module+ reader
   (provide read-syntax))
@@ -16,20 +16,23 @@
    [(:or (from/stop-before "#" "\n")
          (from/to "/*" "*/")) (token 'COMMENT #:skip? #t)]
    [reserved-toks lexeme]
-   [(:seq alphabetic (:* (:or alphabetic) digits)) (token 'ID (string->symbol lexeme))]
-   [(:seq (:? "-") (:+ digits)) (token 'INT (string->number lexeme))]))
+   [(:seq (:? "-") (:+ (:or alphabetic) digits))
+    (let ([maybe-num (string->number lexeme)])
+      (if maybe-num
+          (token 'INT maybe-num)
+          (token 'ID (string->symbol lexeme))))]))
 
 (define-macro top #'#%module-begin)
 
 (define-macro (fun VAR (ARGVAR ...) EXPR)
   #'(define (VAR ARGVAR ...) EXPR))
 
-(define-macro-cases s-or-d
+(define-macro-cases add-or-sub
   [(_ LEFT "+" RIGHT) #'(+ LEFT RIGHT)]
   [(_ LEFT "-" RIGHT) #'(- LEFT RIGHT)]
   [(_ OTHER) #'OTHER])
 
-(define-macro-cases p-or-q
+(define-macro-cases mult-or-div
   [(_ LEFT "*" RIGHT) #'(* LEFT RIGHT)]
   [(_ LEFT "/" RIGHT) #'(/ LEFT RIGHT)]
   [(_ OTHER) #'OTHER])
@@ -37,6 +40,7 @@
 (define-macro app #'#%app)
 
 (define (read-syntax src ip)
+  (port-count-lines! ip)
   (define parse-tree (parse src (λ () (tokenize-1 ip))))
   (strip-bindings
    (with-syntax ([PT parse-tree])