Page 170 - NUMINO Challenge_M1

Numbers

1. Counting Numbers and Digits

EEExxxeeerrrccciiissseee Mia wrote the numbers from 1 through 12 in her notebook.
Mia has written down 12 numbers.
David wrote the numbers from 10 to 22 in his notebook.
David wrote down 22-10+1=13 numbers.
David wrote 1 more number than Mia.

EEExxxeeerrrccciiissseee From 10 to 20, there are 20-10+1=11 numbers.
From 10 to 20, there are 11^2=22 digits.

EEExxxeeerrrccciiissseee If numbers are written from 20, each number would have 2 digits.
2^ =14, =7. Write 7 numbers starting with 20.
20, 21, 22, 23, 24, 25, 26

Type Study The boys are standing in the 1st, 3rd, 5th, 7th, 9th, Positions and the girls are
standing in the 2nd, 4th, 6th, 8th, 10th, positions.
The 10th student is a girl.

The 10th student is a girl, so the next student is a boy. boy girl
20th
10th 11th 12th 13th 14th 1 5 t h 16th 17th 18th 19th

The table in shows that there are 6 girls.

Problem solving

1 The number of marbles is the same as the number of numbers from 9 to 21:

21-9+1=13 marbles.

33Answer Key