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Maths Heuristics Focus: Model-drawing and unitary method. 6 th March 2013. Question 1. Farah has 2 times as many beads as Xena. Xena have 5 beads. How many beads do Farah have? Which model is correct? The orange model or the yellow model?
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Maths Heuristics Focus: Model-drawing andunitary method 6th March 2013
Question 1 • Farah has 2 times as many beads as Xena. Xena have 5 beads. How many beads do Farah have? • Which model is correct? • The orange model or the yellow model? • Explain. ? Farah ? Xena Farah 5 Xena 5
In Edmodo • Which option will you choose?
Farah has 2 times as many beads as Xena. Xena have 5 beads. How many beads do Farah have? • Which number sentence is correct? Option (a)5 units 51 unit 5 ÷ 5 = 12 units 1 x 2 = 2 Farah have 2 beads. Option (b)1 unit 5 2 units 5 x 2 = 10 Farah have 10 beads. ? Farah ? Xena Farah 5 Xena 5
Question 2 • Jenny has 3 times as many beads as Su. Su have 10 beads. How many beads do they have altogether? • Explain how are you going to solve this question?
Question 2 • Jenny has 3 times as many beads as Su. Su have 10 beads. How many beads do they have altogether? • 1 unit 104 units 10 x 4 = 40 • They have 40 beads altogether. Jenny ? Su 10
Question 3 Siti and Mary collected 40 stamps altogether. Mary collected 4 times as many stamps as Siti. (a) How many stamps did Siti collect? (b) How many stamps did Mary collect? • Explain how are you going to solve this question?
Siti and Mary collected 40 stamps altogether. Mary collected 4 times as many stamps as Siti. (a) How many stamps did Siti collect? (b) How many stamps did Mary collect?
Siti and Mary collected 40 stamps altogether. Mary collected 4 times as many stamps as Siti. (a) How many stamps did Siti collect? (b) How many stamps did Mary collect? • a) 8 units 40 • 1 unit 40 ÷ 5 = 8 • Siti collected 8 stamps (b) ? Mary 40 • b) 8 units 40 • 1 unit 40 ÷ 5 = 8 • 4 units 8 x 4 = 32 • Mary collected 32 stamps Siti (a)?
Question 4 • The book costs twice as much as a pen. The pen costs twice as much as a ruler. Their total cost is $20. Find the cost of the pen. • Explain how are you going to solve this question?
The book costs twice as much as a pen. The pen costs twice as much as a ruler. Their total cost is $21. Find the cost of the pen. book • 7 units 21 • 1 unit 21 ÷ 7 = 3 • 2 units 3 x 2 = 6 • The pen cost $6. ? $21 pen ruler