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Material

Answer Key — Lesson 1: Reading & Writing Big Numbers

Teacher answer key for all three versions of the Lesson 1 worksheet (place value to tens of thousands). Brief working and "look-fors" are included where they help marking. ULO1.

Main — "Counting the Big Gumnut Pile"

  1. a) two thousand, four hundred and eight   b) ten thousand and sixty
  2. a) 6 320   b) 19 005
  3. a) 700 (seven hundred)   b) 30 000 (thirty thousand)
  4. 8 367 = 8 000 + 300 + 60 + 7
  5. 925, 5 020, 5 200, 12 100
  6. Largest 7 530; smallest 3 057. Look for: a leading 0 is not allowed for the smallest, so 0 goes in the tens/hundreds, not the front.

Support — "Place value with a helping chart"

  1. Thousands 2, Hundreds 4, Tens 6, Ones 3.
  2. a) fifty (1 250 = one thousand, two hundred and fifty)   b) three thousand, four hundred
  3. 2 106
  4. a) 540   b) 2 300

Extension — "Bigger numbers and reasoning"

  1. a) forty-six thousand, three hundred and nine   b) eighty thousand and seventy
  2. a) 5 000   b) 50 000. Look for: in 55 200 the first 5 is 50 000 and the second is 5 000; answer asks the value of each named 5.
  3. Largest 96 310; smallest 10 369. Reasoning: biggest digit in the highest place for largest; smallest non-zero digit leads for smallest.
  4. 24 thousands, 18 hundreds, 5 tens, 12 ones → 24 000 + 1 800 + 50 + 12 = 25 862. Look for: students must trade the over-9 columns up.
  5. Any two of 30 020, 30 040, 30 063 (tens digit double the ones, other digits 0, between 30 000–40 000). E.g. 30 021, 30 042, 30 063, 30 084.