Page 183 - NUMINO Challenge_M1

Answer
Key

Problem solving

1 Reading a number upside down is the same as turning the number half turn. The

following shows the number of pens that Christine had to buy if it is turned half turn.
61 19
Christine was supposed to buy 19 pens.

2 In order to find the original shape before it was turned a quarter turn to the right,

the new figure must be turned a quarter turn to the left.

2. Mirror Reflection of Shapes
EEExxxeeerrrccciiissseee The shape reflected on a mirror switches the left and right sides.

Jessica is actually making a “V” with her left hand.
EEExxxeeerrrccciiissseee The image of a stamp is the same as the image on the reflection of a mirror.

In order to stamp “Jay”, the stamp must be carved as “ yaJ ”, which the left
and right are switched.

yaJ Jay

EEExxxeeerrrccciiissseee When a mirror reflects the subtraction expression, the left and right are
switched.

Original expression mirror Mirror reflection

The Original subtraction expression is 69-18, which equals 51.

46 NUMINO Challenge M1