Froggy Jumps Mastering Multi-Digit MathOnline version Test your skills in addition and subtraction with multi-digit numbers! by Ahmad Ali 1 450 + 50 = a 500 b 600 c 700 2 1000 - 350 = a 55 b 155 c 650 3 29+ 2 = a 51 b 41 c 31 4 850 + 150 = a 1000 b 565 c 585 5 78 + 2 = a 80 b 90 c 1000 6 900 - 400 = a 500 b 454 c 434 7 12 + 5 = a 7 b 17 c 8 8 800 - 400 = a 500 b 400 c 511 9 345 + 5 = a 350 b 450 c 550 10 1000 - 880 = a 120 b 122 c 102