Class 3 IMO : Papers

Grade 3 IMO papers

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Grade 3 Maths (IMO) : Division

Let’s talk about what division really is — it is repeated subtraction; much the way multiplication is repeated addition.

Let’s say I have the basic problem 16 ÷  4.  I could start with 16 and then subtract 4, subtract another 4, another 4, and another 4 until I run out and reach zero.  I would have to do this 4 times. If I had 16 cookies that I wanted to share equally among 4 friends, I could do the “one for you, one for you, one for you, and one for you” process and still end up with 4 cookies for each.

But what about 375 ÷ 50? If I don’t know how to divide by double digit numbers, the repeated subtraction process might actually be a good choice . . . at least showing some number sense to know that 375 divided by 50 means “How many 50’s in 375?” I know if I subtract 50 six times, I still have 75 left. I can subtract another 50 and I have 25 left over. So 375 ÷ 50 = 7 with a remainder of 25.

Dividing using the distributive law

Division Possible Split Calculation Answer
69 ÷ 3 60 + 9 (60 ÷ 3) = 20

(9 ÷ 3)  = 3

20 + 3 = 23
391 ÷ 3 390 + 1  (390 ÷ 3) = 130

(1 ÷ 3) = cannot be divided

130 with Remainder 1

 Long Division

Before a child is ready to learn long division, he/she has to know: Continue reading

Grade 3 Maths (IMO) : Number sense

Place value and Face value

Face value of a digit  is the digit itself whereas Place value can be termed as the location of the digit in the numeral.

 

The value of a place in the place value chart is 10 times the value of the place just to its right.

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Grade 3 Maths (IMO) : Multiplication Strategies

A quick look at the grade 2 lesson on introduction to multiplication

Taming the tables – Tips to introduce multiplication

While multiplying always remember :

An even number  x an even number = an even number

An odd number x an even number = an even number

An odd number x an odd number = an odd number

Distributive property of multiplication

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Grade 3 Maths (IMO) : Addition strategies

Listing down some methods to simplyfy addition.

  • Doubles (such as 6 + 6)
  • Near doubles: Try adding a double and the remainder. Solve 7 + 6,  (6 + 6+ 1) or (7 + 7 – 1).
  • Making a ten or a multiple of 10: To add 7 + 6, I can take 3 from the 6 and put it with the 7 to make 10 and 3. This holds good even with multiples of 10 like 20, 30 40, etc
  • 1 more, 1 less: Show problems such as: 8 + 1, 51 + 1, and 6 – 1, 22-1
  • Place value Decomposition: 35 + 22 can be decomposed into tens and ones 30+20 added to 5+2. Or 35 – 22 can be decomposed to 30-20 plus 5-2.

Pictorial representation of the strategies above :