McGregor Grouping and Ungrouping Lesson
- 2. Stack numbers Match up numbers on right Add numbers in each column Answer below “equals line” Add from right left Does not matter which number on top/bottom KEEP THINGS NEAT!!!
- 4. 1283 + 532 = 1283 +532 ------------
- 5. Cube = 1,000 units Square (flat) = 100 units Long rectangle (long) = 10 units Small square (unit) = 1 unit
- 6. +
- 7. 10 longs = 1 flat
- 9. 1283 1 + 532 1283 ---------- + 532 5 ---------- 15 1 1283 + 532 ---------- 1815
- 10. + 374 + 258 = 632
- 11. 11 374 +258 -------- 632 374 + 258 = 632
- 12. Stack numbers Make sure larger number is on top Match up numbers on right Subtract numbers in each column Subtract from right left KEEP THINGS NEAT!!!
- 13. 1524 - 853 ----------- 1 ***Notice 5 cannot be subtracted from 2***
- 14. - 1524 – 853 = 671
- 15. Subtract 3 units(ones) 1524 – 853 = 671
- 16. Not enough longs (tens) to subtract from so… 1524 – 853 = 671
- 17. Break flat (hundred) into longs (tens) “UNGROUP” 1524 – 853 = 671
- 18. Now you can take the 5 tens away 1524 – 853 = 671
- 19. 8 hundreds cannot be subtracted from only 4 so… UNGROUP!!! 1524 – 853 = 671
- 20. Break cube into its 10 flats 1524 – 853 = 671
- 21. Subtract 8 of the flats 1524 – 853 = 671
- 22. Now just count what is left… Flats (100) = 6 Longs (10) = 7 Units (1) = 1 600 + 70 + 1 = 671 1524 – 853 = 671
- 23. 1524 - 853 ----------- 1 ***Notice 5 cannot be subtracted from 2***
- 24. 4 12 1524 - 853 --------- 71 Break apart one of the hundreds (flats) and add the resulting tens (longs) to the two.
- 25. 14 0 4 12 1524 - 853 --------- 671 Break a thousand (cube) and add the hundreds to the existing hundreds.
Editor's Notes
- #19: Notice the flat broken apart has now disappeared