
Negator and the other SUMDIALS were created by Peter Shannon, Principal Teacher of Mathematics at Boroughmuir High School.
SUMDIALS
The NEGATOR is one of six complementary aids. They enable pupils to understand
ADDITION and SUBTRACTION facts UP to 10
ADDITION and SUBTRACTION facts UP to 20
MULTIPLICATION and DIVISION facts UP to 50
MULTIPLICATION and DIVISION facts UP to 100
the FOUR RULES (+, -, ×, ÷) for DIRECTED NUMBERS
the TRIG. RATIOS of ANY ANGLE
Further information and SUMDIALS are availble from
SUMDIALS LIMITED
477 GORGIE ROAD
EDINBURGH
EH11 3AD
Tel: +44(0)131 443 5000 Fax: +44(0)131 444 0438