Grade 3 IMO papers
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Grade 4 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.
Grade 3 Maths (IMO) : Multiplication Strategies
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
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 :
Grade 1 Math : Number sense : Tens and Ones
Worksheets for practice
Grade 1 Place Value Worksheet – 2-digit numbers1
