Difference between revisions of "Multiplication by 10, 100, 1000"
From wikisori
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=== Age === | === Age === | ||
− | 6-9.<br> | + | 6-9.<br> |
=== Materials === | === Materials === | ||
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=== Preparation === | === Preparation === | ||
− | This activity is a prerequisite for the small bead frame<br> | + | This activity is a prerequisite for the small bead frame<br> |
=== Presentation === | === Presentation === | ||
#The directress isolates a 10-bar. | #The directress isolates a 10-bar. | ||
− | #Directress asks the | + | #Directress asks the child; "How many units are there in 10?" 10. |
#The directress isolates a hundred square and asks the child; "How many tens are there in 100?" "How many units?" | #The directress isolates a hundred square and asks the child; "How many tens are there in 100?" "How many units?" | ||
#Isolate the cube. Ask: "How many hundreds are there in 1000? How many units? tens?" | #Isolate the cube. Ask: "How many hundreds are there in 1000? How many units? tens?" | ||
Line 22: | Line 22: | ||
#With the child draw relative conclusions of all the changes possible. | #With the child draw relative conclusions of all the changes possible. | ||
− | '''By ten<br>''' | + | '''By ten<br>''' |
Directress write down a multiplication problem and ask the child to lay out the problem, using the golden bead material i.e. ( 21 x 10 =). | Directress write down a multiplication problem and ask the child to lay out the problem, using the golden bead material i.e. ( 21 x 10 =). | ||
Line 42: | Line 42: | ||
#Notice that the product has the same number of zeros as the multiplier. | #Notice that the product has the same number of zeros as the multiplier. | ||
− | '''By one thousand <br>''' | + | '''By one thousand <br>''' |
#Directress write the problem 4 x 1000 =. | #Directress write the problem 4 x 1000 =. | ||
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=== Control Of Error === | === Control Of Error === | ||
− | <br> | + | <br> |
=== Points Of Interest === | === Points Of Interest === | ||
− | <br> | + | <br> |
=== Purpose === | === Purpose === | ||
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*To prepare the child for multiplication using the bead frames. | *To prepare the child for multiplication using the bead frames. | ||
− | <br> | + | <br> |
=== Variation === | === Variation === | ||
− | <br> | + | <br> |
=== Links === | === Links === | ||
− | <br> | + | <br> |
=== Handouts/Attachments === | === Handouts/Attachments === | ||
− | <br> | + | <br> |
− | [[Category:Mathematics]][[Category:Mathematics_6-9]] | + | [[Category:Mathematics]] [[Category:Mathematics_6-9]] |
Latest revision as of 05:17, 22 July 2009
Contents
Age
6-9.
Materials
- Decimal system materials
- Paper
- Black and red pencils
Preparation
This activity is a prerequisite for the small bead frame
Presentation
- The directress isolates a 10-bar.
- Directress asks the child; "How many units are there in 10?" 10.
- The directress isolates a hundred square and asks the child; "How many tens are there in 100?" "How many units?"
- Isolate the cube. Ask: "How many hundreds are there in 1000? How many units? tens?"
- "We can say that 10 tens is the same as 100, 100 tens is the same as 1000 and so on. "
- With the child draw relative conclusions of all the changes possible.
By ten
Directress write down a multiplication problem and ask the child to lay out the problem, using the golden bead material i.e. ( 21 x 10 =).
- The child, knowing the function of multiplication, combines these quantities and makes the necessary changes.
- With the answer - two hundreds, one ten, and the zero is written in red. 21x10 = 210 .
- Observe that the product is simply 21 (the multiplicand) with a zero after it.
- Do many examples of this type, including: 30 x 10 = 300
By one hundred
- Directress write down a multiplication problem such as 23 x 100 = and asks the child to lay out the material.
- We can't put out 23 one hundred times, we would run out of beads!
- We can multiply each unit by 100. Isolate one bead from the 23.
- 1 x 100 = 100 Substitute the bead for a hundred square.
- Repeat for the other two units. Then 10 x 100 = 1000.
- Replace each ten bar with a thousand cube, and so on.
- Record the product. 23 x 100 = 2300.
- Notice that the product has the same number of zeros as the multiplier.
By one thousand
- Directress write the problem 4 x 1000 =.
- As before, multiply each unit by 1000, replacing each bead with a thousand cube.
- Record the product 4 x 1000 = 4000. In this case we jumped from the units, past the tens, past the hundreds, to the thousands.
- For each hierarchy that we increased, one zero was added.
- Observe as before that the number of zeros in the product is the same as the number of zeros in the multiplier.
- The product is simply the number of zeros in the multiplier.
Control Of Error
Points Of Interest
Purpose
Direct Aim:
- to be sure that the child has understood the concept of change
- To ease of multiplying by powers of ten, and understanding of the characteristic patterns of such multiplication.
Indirect Aim:
- To prepare the child for multiplication using the bead frames.
Variation
Links
Handouts/Attachments