Doing simple math in your head /

समान संसाधन

• Estimation and mental computation : 1986 yearbook /
  प्रकाशित: (1986)
• Money and maths in everyday life
  द्वारा: Belsten, D. G.
  प्रकाशित: (1984)
• Arithmetic /
  द्वारा: Steinhoff, Richard L.
  प्रकाशित: (1978)
• Arithmetic for the modern age /
  द्वारा: Bakst, Aaron
  प्रकाशित: (1960)
• Arithmetic for the practical worker /
  द्वारा: Thompson, James E.
  प्रकाशित: (1962)