456+109
=(450+6)+(100+9)
=450+6+100+9
=(450+100)+(6+9)
=550+15
=565
456-109
=(450+6)-(100+9)
=450+6-100-9
=(450-100)+(6-9)
=350-3
=347
456+109
=(450+6)+(100+9)
=450+6+100+9
=(450+100)+(6+9)
=550+15
=565
456-109
=(450+6)-(100+9)
=450+6-100-9
=(450-100)+(6-9)
=350-3
=347