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The Brandywine School District presents The Singapore Math Series Session 1I Addition and Subtraction Created by Hester Sutton March 2011 A man sold 230 balloons at a carnival in the morning. He sold another 86 balloons in the evening. a) How many balloons did he sell in all? b) How many more balloons did he sell in the morning than in the evening? A man sold 230 balloons at a carnival in the morning. He sold another 86 balloons in the evening. a) How many balloons did he sell in all? Morning Afternoon 230 86 ? A man sold 230 balloons at a carnival in the morning. He sold another 86 balloons in the evening. How many did he sell in all? Hundreds Tens Ones 3 1 6 Using Number Bonds Addition part + part = whole 230 316 whole part 86 part A man sold 230 balloons at a carnival in the morning. He sold another 86 balloons in the evening. a) How many balloons did he sell in all? (230 230 300+16=316 + 70)+16 86 (70+16) 316 balloons were sold in all. A man sold 230 balloons at a carnival in the morning. He sold another 86 balloons in the evening. a) How many balloons did he sell in all? b) How many more balloons did he sell in the morning than in the evening? A man sold 230 balloons at a carnival in the morning. He sold another 86 balloons in the evening. b) How many more balloons did he sell in the morning than in the evening? 230 Morning Evening 86 ? A man sold 230 balloons at a carnival in the morning. He sold another 86 balloons in the evening. How many more balloons did he sell in the morning than in the evening? Hundreds 1 Tens Ones 4 4 Using Number Bonds Subtraction whole - part = part 230 whole 86 part 144 part Mary made 686 paper flowers. She sold some of them. If 298 were left over, how many flowers did she sell? Using the Bar Model Mary sold 384 flowers. 298 ? Mary’s Paper Flowers 686 686 - 298 686 – 300 + 2 = 386 + 2 = 388 Mary made 686 paper flowers. She sold some of them. If 298 were left over, how many flowers did she sell? Using Number Bonds ? Part 686 Whole 298 Part 686 - 298 = 388 hundreds tens ones 134 girls and 119 boys took part in an art competition. How many more girls than boys were there? Comparison bar model. 134 girls boys 119 Using a mental math strategy: 134 - 119 134 – 120 + 1 14 + 1 = 15 There were 15 more girls than boys. ? John read 32 pages in the morning. He read 14 fewer pages in the afternoon. a) How many pages did he read in the afternoon? b) How many pages did he read altogether? 32 Morning Afternoon ? 14 32 – 14 = 18 John read 18 pages in the afternoon. 14 Part 32 Whole ? Part John read 32 pages in the morning. He read 14 fewer pages in the afternoon. a) How many pages did he read in the afternoon? b) How many pages did he read altogether? 32 Morning ? Afternoon 18 32 + 18 = 50 John read 50 pages altogether. 32 Part ? Whole 18 Part Addition - Thousands A shop sold 957 beef burritos and 1238 chicken burritos. How many burritos were sold altogether? 957 1238 ? 957 Part 2195 Whole 1238 Part 957 +1238 = 2195 Thousands Hundreds Tens Ones The total weight of Peter, David, and Henry is 123 kg. + D +than = 123 kgis 3 kg Peter D+15 is 15 kg heavier David. David D+3 lighter than Henry. Find Henry’s weight. Peter 15kg 123 kg David Henry 3kg D+15 + D + D+3 = 123 kg D + D + D + 18 = 123 kg D + D + D = 105 kg D = 35 kg H = (35 + 3)kg H = 38 kg Henry weighs 38 Kg