Page 157 - NUMINO Challenge_M2

AnswerType Study
Key

After the 4th round, Jim gave Ashley 2 rocks and had none left.
Jim had 2 rocks before the 4th round.

Jim Ashley Jim s rocks

Round Ashley gives Jim 2 rocks. 4 rocks
1
6 rocks
Round
2 Jim gives Ashley 2 rocks. 4 rocks

Round Jim gives Ashley 2 rocks. 2 rocks
3
Jim gives Ashley 2 rocks. 0 rocks
Round
4

In the beginning, Jim and Ashley had the same number of rocks, so they
each had 4 rocks.

Problem solving

1 When the solid board is removed, the same amount of height that is decreased

on the left side is increased on the right side. The height of the water in the
water tank will be the same all across when the board is removed.

Amount of height that is 1 cm 2 cm 3 cm 4 cm 5 cm
decreased on the left side 19 cm 18 cm 17 cm 16 cm 15 cm
11cm 12 cm 13 cm 14 cm 15 cm
Height of water
on the left side

Height of water
on the right side

When the height of the water on the left side decreases by 5 cm, the height is
15 cm. When the height of the water on the right side increases by 5 cm, the

height is 15 cm.
The height of the water is 15 cm.

2 After Peter received the same amount of money that he already had, his total

was 20 cents. The amount of money he had was , and the amount of money
he received from Marina was . + =20 cents, so =10 cents.

After giving Peter 10 cents, Marina had 20 cents, so she originally had
30 cents.

20 NUMINO Challenge M2