Year 2 - Lesson 13

Kangaroo problems edited from 2011 and 2010 – we’re getting ready for the Math Kangaroo

1.      Fourteen children lined up in pairs. How many pairs were there?

The don’t really know how to divide numbers yet, so they drew 14 dots, circled two at a time and then counted how many circles they have.

2.     Today it is March 18, 2010, and I am 7 years old. How old will I be on March 18, 2020?

The kids counted how many years is it from 2010 to 2020 and then added that number to 7.

3.     There were 9 four-person tables in the room where Max had his birthday party. When Max and all his guests sat down, there were still 7 empty seats. How many guests came to Max’s party?

One of the kids organized everyone to draw tables and count seats. J Then he told them to subtract 7 from that number. Wow, good management skills :)

4.     Sasha had $20. He bought one carton of milk, 10 bananas, one loaf of bread and two packages of butter. With the money he had left over, he bought lollipops. How many lollipops did he buy?

a)     Milk: $2,

b)     Lollipop: $1.50,

c)      Bread: $2,

d)     Butter: $2.50,

e)     10 Bananas: $5

            This is a relatively simple counting problem – I presented it like a working-backwards puzzle to the kids so that they get more familiar with working backwards in problems.

5.     Matthew has 3 pieces of candy, Katya has 2 pieces of candy less than Dima, and Dima has 4 times as many pieces of candy as Matthew. How many pieces of candy do Matthew, Katya, and Dima have altogether?

This one was pretty easy they figured it out after a few moments of calculating and scribbling.

6.     Today is 3/12/2011. No item can be sold after the date shown next to it. Which of the items cannot be sold?

a)     Cheese: 9/15/2011

b)     Juice: 3/4/2012

c)      Butter: 7/11/2011

d)     Yogurt: 2/25/2011

It can never hurt to know how the calendar works.

7.      In 36 years, I will be 100 years old. How old am I now?

Another backwards problem solving problem. When they solved they were like “Oh really you’re 64? Oh we thought you were younger…” Haha for a few moments they actually believed it

8.     Katya has several dogs and 4 cats. The number of her cats’ ears is equal to the number of her dogs’ paws. How many dogs does Katya have?

The thought about how many ears each cat has, then added it together for all the cats, and then split that amount to be four legs of the dogs.

9.     Mr. and Mrs. Kangaroo have three daughters. The youngest is 5 years old. The middle daughter is 4 years younger than the oldest daughter and 6 years older than the youngest daughter. How old is the Kangaroos’ oldest daughter?

Another problem where to solve the problem you first have to read the whole problem and only then you can solve it. This is good practice.

10.  Play “I’m thinking of a domino that…” by giving hints about the domino and having the kids rule out all the other dominoes until they get to that one. If there is still time left, play Chocolate Fix.

This was a nice cool-down game but the kids were all really tired by then (remember, they’re coming after school and it’s spring now and their stored energy from sitting in school all day long for a year is starting to escape J)

Only a couple kids stayed to do Chocolate Fix – the others ran off to play. This is actually a very good mental rotation game and also it involves thinking in a venn-diagram-y type of way – the different clues have to overlap in your mind to solve the puzzle.