Adding Two Numbers Directly.Another term for directly is “no synthesis.” When adding directly...

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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

3+1 = 4

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

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

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

2+2 = 4

From http://www.uabacus.arizona.edu/Developed by Dr. L. Penny Rosenblum

Try doing 6 + 3 on your own. Say the steps!

6 + 3 = 9

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

30 + 50 = 80

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 = 80From http://www.uabacus.arizona.edu/

Developed by Dr. L. Penny Rosenblum

Try doing 60 + 10 on your own. Say the steps!

60 + 10 = 70

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 = 70From http://www.uabacus.arizona.edu/

45 + 3 = 48

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

27 + 60 = 87

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 = 87From http://www.uabacus.arizona.edu/

55 + 20 = 75

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

13 + 26 = 39

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 = 39From http://www.uabacus.arizona.edu/

46 + 52 = 98

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 = 98From http://www.uabacus.arizona.edu/

247 + 601 = 848

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

567 +321 = 888

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 = 888From http://www.uabacus.arizona.edu/

Adding Two Numbers Directly.Another term for directly is “no synthesis.” When adding directly...

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