GoalUse the place value mat to read the value of each digit and to make the greatest 4-digit number from digit cards.
New words
digit · one of the ten symbols 0 to 9place value · what a digit is worth because of its place in a numbergreatest · the biggest
Explanation
The value of a digit depends on its place. On the place value mat the places, from the left, are thousands, hundreds, tens and ones. In 5,284 the 5 is in the thousands place, so it is worth 5,000. The 2 is worth 200, the 8 is worth 80 and the 4 is worth 4. We write a comma after the thousands. To make the greatest number from digit cards, put the biggest digit in the highest place, the next biggest in the next place, and so on. If there are more cards than places, leave out the smallest card. A zero is never put at the front of a 4-digit number.
5,284 = 5,000 + 200 + 80 + 4
Thousands
Hundreds
Tens
Ones
5
2
8
4
Worked examples
Thousands
Hundreds
Tens
Ones
7
0
6
1
In 7,061 the 7 is worth 7,000, the 0 is worth 0 hundreds, the 6 is worth 60 and the 1 is worth 1. The zero is still important: it keeps the 6 in the tens place and the 7 in the thousands place.
Thousands
Hundreds
Tens
Ones
Discard
9
8
6
3
1
Youssef has the cards 8, 3, 6, 1 and 9, and four boxes. To make the greatest number he leaves out the smallest card, 1, and puts the others from biggest to smallest: 9, 8, 6, 3. The number is 9,863.
Thousands
Hundreds
Tens
Ones
Discard
9
7
5
4
1
Mariam draws her cards one at a time: 9, 4, 7, 1, 5. She puts 9 in the thousands at once. She puts 4 in the ones, 7 in the hundreds, the 1 in the discard box and 5 in the tens. Her number is 9,754, the greatest she could make from these cards.
Class activity
Biggest and smallest. Write the digits 0 to 9 on ten paper cards. Draw four cards at once. Make the greatest and the smallest 4-digit number you can, using all four cards, and remember that a number cannot start with 0. Your partner checks both numbers. Play 5 rounds and write the numbers in a table.
Practice
1
What is the value of the 8 in 3,872?
800.
2
Look at the mat. Which digit is in the tens place?
Thousands
Hundreds
Tens
Ones
4
3
0
5
0. The number is 4,305.
3
The cards are 2, 7, 4, 9 and 1. Make the greatest 4-digit number from four of them.
9,742. The card 1 is left out.
4
The cards are 5, 0, 8 and 3. Make the smallest 4-digit number using all of them.
3,058. The 0 cannot go first, so 3 goes first and then 0, 5, 8.
5
Farida’s number has 6 in the thousands place, 0 in the hundreds, 9 in the tens and 2 in the ones. Write her number.
