Mental Math 1Versión en línea Squares and Multiplication por Georgios Michalopoulos 1 35 * 35 Written answer 2 65 * 65 Written answer 3 95 * 95 Written answer 4 84 * 86 Written answer 5 81 * 89 Written answer 6 53 * 57 Written answer 7 13 * 14 Written answer 8 17 * 15 Written answer 9 15 * 14 Written answer 10 18 * 13 Written answer 11 12 * 16 Written answer 12 19 * 19 Written answer Feedback 1 Squares of numbers that end in 5 always end in 25. 3 * (3 + 1) = 12 2 Squares of numbers that end in 5 always end in 25. 6 * (6 + 1) = 42 3 Squares of numbers that end in 5 always end in 25. 3 * (9 + 1) = 90 4 8 * (8 +1) = 72 4 * 6 = 24 5 8 * 9 = 72 1 * 9 = 09 7 (13 + 4) * 10 = 170 3 * 4 = 12 170 + 12 = 182 8 (17 + 5) * 10 = 220 5 * 7 = 35 220 + 35 = 255 9 (15 + 4) * 10 = 190 5 * 4 = 20 190 + 20 = 210 10 (18 + 3) * 10 = 210 8 * 3 = 24 210 + 24 = 234 11 (12 + 6) * 10 = 180 2 * 6 = 12 180 + 12 = 192 12 (19 + 9) * 10 = 280 9 * 9 = 81 280 + 81 = 361
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