Regrouping Ones, Tens and Hundreds

Regrouping Ones, Tens and Hundreds exercise

• How many ones blocks are needed to regroup to a tens rod?

  Hints

  You can regroup base ten blocks so they are easier to count.

  • There are 10 tens in 1 hundred.
  • How many ones are in 1 ten?

  • This is 1 ones block.
  • How many of these do you need to highlight to equal 1 ten?

  Solution

  All 10 ones blocks needed highlighting.

  You need to regroup 10 ones blocks to make 1 ten.

• How can we regroup these amounts?

  Hints

  • Start by regrouping the ones.
  • How many tens are in 23?

  • Start by regrouping the ones.
  • How many tens are in 42?

  Solution

  • 2 tens + 3 ones = 23 ones
  • 4 tens + 2 ones = 42 ones

• Use what you know to regroup the blocks in the picture below.

  Hints

  Start by regrouping the ones. How many tens in 13?

  There is one ten in 13. How many ones are left?

  The correct answer will equal 83.
  7 tens + 13 ones = 83
  70 + 13 = 83

  Solution

  7 tens + 13 ones = 83

  • First, regroup the ones. 13 ones = 1 ten + 3 ones
  • Next, add the tens. 7 tens + 1 ten = 8 tens
  • The correct answer is: 8 tens + 3 ones = 83*

• How can you regroup the hundreds?

  Hints

  First, regroup the hundreds to the thousands place value.
  10 hundreds = 1 thousand.

  12 hundreds is equal to 1 thousands block + 2 hundreds blocks.

  Solution

  Remember, 10 hundreds = 1 thousand, so if you regroup these hundreds, you get:

  • 12 hundreds = 1 thousand + 2 hundreds = 1,200
  • 15 hundreds = 1 thousand + 5 hundreds = 1,500
  • 20 hundreds = 2 thousands = 2,000
  • 23 hundreds = 2 thousands + 3 hundreds = 2,300

• How many tens make one hundred?

  Hints

  • 10 ones are the same amount as 1 ten .
  • How many tens are the same amount as 1 hundred?

  • This is 1 tens block.
  • How many of these do you need to highlight to equal 1 hundred?

  Solution

  All 10 tens rods needed highlighting.

  To make 1 hundred, you regroup 10 tens rods.

• Use what you know to regroup the blocks in the picture below.

  Hints

  First, regroup the ones. How many tens are in 12 ones?

  Next, regroup the tens into hundreds. Remember: there are 10 tens in 1 hundred.

  Finally, regroup the hundreds into thousands. 10 hundreds is equal to 1 thousand.

  Solution

  You can regroup the ones into tens, the tens into hundreds and the hundreds into thousands to equal 1,462.