Adding Two Numbers Directly
160 likes | 251 Vues
Adding Two Numbers Directly. .Another term for directly is “no synthesis.” When adding directly all the beads you need are available to push to the separation bar.
Adding Two Numbers Directly
E N D
Presentation Transcript
Adding Two Numbers Directly .Another term for directly is “no synthesis.” When adding directly all the beads you need are available to push to the separation bar. From http://www.uabacus.arizona.edu/ Developed by Dr. L. Penny Rosenblum
Set three 1-beads in the units column.Ask: “Can I add 1 directly?”Answer” “Yes I can.”Set a 1-bead in the units column.You now have 4 beads in the unit column.Sum = 4 3+1 = 4 From http://www.uabacus.arizona.edu/ Developed by Dr. L. Penny Rosenblum
5+3 = 8 • Set a 5-bead in the units column.Ask: “Can I add 3 directly?”Answer” “Yes I can.”Set three 1-beads in the units column.You now have 8 beads in the units column.Sum = 8 From http://www.uabacus.arizona.edu/ Developed by Dr. L. Penny Rosenblum
2+2 = 4 • Set two 1-beads in the units column.Ask: “Can I add 2 directly?”Answer” “Yes I can.”Set two 1-beads in the units column.You now have 4 beads in the units column.Sum = 4 From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Try doing 6 + 3 on your own. Say the steps! From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Set a 5-bead and a 1-bead in the units column.Ask: “Can I add 3 directly?”Answer” “Yes I can.”Set three 1-beads in the units column.You now have 9 beads in the units column.Sum = 9 6 + 3 = 9 From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Set three 1-beads in the tens column.Ask: “Can I add 50 directly?”Answer” “Yes I can.”Set a 5-bead in the tens column.You now have 8 beads in the tens column.Sum = 80 30 + 50 = 80 From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Try doing 60 + 10 on your own. Say the steps! From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Set a 5-bead and a 1-bead in the tens column.Ask: “Can I add 10 directly?”Answer” “Yes I can.”Set a 1-bead in the tens column.You now have 7 beads in the tens column.Sum = 70 60 + 10 = 70 From http://www.uabacus.arizona.edu/ Developed by Dr. L. Penny Rosenblum
Set four 1-beads in the tens column and a 5-bead in the units column.Ask: “Can I add 3 directly?”Answer” “Yes I can.”Set three 1-beads in the units column.Sum = 48 45 + 3 = 48 From http://www.uabacus.arizona.edu/ Developed by Dr. L. Penny Rosenblum
Set two 1-beads in the tens column and 7 beads in the units column.Ask: “Can I add 60 directly?”Answer” “Yes I can.”Set a 5-bead and a 1-bead in the tens column.Sum = 87 27 + 60 = 87 From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Set a 5-bead in the tens column and a 5-bead in the units column.Ask: “Can I add 20 directly?”Answer” “Yes I can.”Set two 1-beads in the tens column.Sum = 75 55 + 20 = 75 From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Set a 1-bead in the tens column and three 1-beads in the units column.Ask: “Can I add 20 directly?”Answer” “Yes I can.”Set two 1-beads in the ten column. • Ask “Can I add 6 directly?” • Answer” “Yes I can.”Set a 5-bead and a 1-bead in the units column.Sum = 39 13 + 26 = 39 From http://www.uabacus.arizona.edu/ Developed by Dr. L. Penny Rosenblum
Set four 1-beads in the tens column and 6 beads in the units column.Ask: “Can I add 50 directly?”Answer” “Yes I can.”Set a 5-bead in the tens column. • Ask “Can I add 2 directly?” • Answer” “Yes I can.”Set two 1-beads in the units column.Sum = 98 46 + 52 = 98 From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum
Set two 1-beads in the hundreds column, four 1-beads in the tens column and 7 beads in the units column.Ask: “Can I add 600 directly?” Answer” “Yes I can.” Set 600 in the hundred columns. • Ask: “Can I add 0 directly?” Answer” “Yes I can.” Set 0 by tapping the silver bar in the tens column.Ask: “Can I add 1 directly?” Answer” “Yes I can.” Set 1 in the units column.Sum = 848 247 + 601 = 848 From http://www.uabacus.arizona.edu/ Developed by Dr. L. Penny Rosenblum
Set a 5-bead in the hundreds column, 6 beads in the tens column and 7 beads in the units column.Ask: “Can I add 300 directly?” Answer” “Yes I can.” Set 300 in the hundred columns. • Ask: “Can I add 20 directly?” Answer” “Yes I can.” Set 20 in the tens column.Ask: “Can I add 1 directly?” Answer” “Yes I can.” Set 1 in the units column.Sum = 888 567 +321 = 888 From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum