โ˜ฐ Year plan ยท Mathematics

Division strategies and story problems

Week 13 ยท Division strategies and story problems ยท 3 lessons
1

Division patterns and place value

Discover Mathematics P4: Term 1, Unit 7, Lessons 11โ€“16
GoalUse place value and basic facts to divide hundreds and thousands.
New words
dividend ยท the number that is divideddivisor ยท the number we divide byquotient ยท the answer of a division
Explanation

In 900 รท 3 = 300, the number 900 is the dividend, 3 is the divisor and 300 is the quotient. Division patterns come from place value. Think of 900 as 9 hundreds. Share 9 hundreds into 3 equal groups: each group gets 3 hundreds, which is 300. We used the basic fact 9 รท 3 = 3 and kept the unit, hundreds. In the same way 3,500 รท 7 is 35 hundreds รท 7 = 5 hundreds = 500. And 480 รท 8 is 48 tens รท 8 = 6 tens = 60. So: find the basic fact, then put back the zeros. Check by multiplying: 300 ร— 3 = 900. Take care with the zeros: 3,000 รท 5 is 30 hundreds รท 5 = 6 hundreds = 600, not 60.

DivisionBasic factUnitQuotient
900 รท 39 รท 3 = 3hundreds300
3,500 รท 735 รท 7 = 5hundreds500
480 รท 848 รท 8 = 6tens60
Worked examples
Find 900 รท 3. 9 hundreds รท 3 = 3 hundreds, so 900 รท 3 = 300. Check: 300 ร— 3 = 900.
Find 3,500 รท 7. 35 hundreds รท 7 = 5 hundreds = 500. The fact 35 รท 7 = 5 gives the digit, the hundreds give two zeros. Check: 500 ร— 7 = 3,500.
Find 480 รท 8. 48 tens รท 8 = 6 tens = 60. Check: 60 ร— 8 = 480.
Class activity

Zero hunt. Write 12 รท 3 = 4. Then write 120 รท 3, 1,200 รท 3 and 12,000 รท 3 with the answers. Count the zeros in each dividend and in each quotient. What do you notice?

Practice
1
Find 800 รท 4.
2
Find 2,700 รท 9.
3
Find 560 รท 7.
4
4,200 LE is shared equally between 6 workers. How much does each worker get?
5
Omar says 3,000 รท 5 = 60. Find his mistake and the right answer.